Flatten | DbMetaDataFactory -> SqlMetaDataFactory (#3818)

* Remove unnecessary references to DbMetaDataFactory

* Remove unnecessary cacheMetaDataFactory parameter and logic

* Remove unused capability to provide normalized server version

SqlConnectionFactory always passed the same value to both parameters

* Convert CollectionDataSet property to auto-property

* Cleanup of SqlMetaDataFactory prior to merge

Convert the list of unsupported engines to a static variable.
Make the UDT/TVP processing methods static.
Change name of constants and ServerVersion parameter to fit naming conventions.
Introduce constant for EngineEdition query.
Reuse SqlCommand where possible.
Remove layer of indentation for using block.
Remove redundant client-side checks for null on fields which are declared as non-nullable within SQL Server.
Slightly simplify building of assembly qualified names.
Convert checks whether columns exist in a DataTable (and DataTables in a DataSet) to debug assertions, since these are statically built now.

* Cleanup of DbMetaDataFactory prior to merge

Move constants which were only used in one method to that method.
Replace an unnecessary string[] allocation with a stack-allocated ReadOnlySpan<string>.
Where appropriate, use ?..
Replace == null and != null with pattern matching.
Convert checks whether columns exist in a DataTable (and DataTables in a DataSet) to debug assertions, since these are statically built now.
Replace use of GetSchemaTable with GetColumnSchema to reduce allocations.
Where appropriate, make methods private and/or static.
Remove unnecessary ADP.CompareInsensitiveInvariant helper.
Simplify IncludeThisColumn to make use of Contains or IndexOf where necessary.

* Merge logic to create CollectionDataSet

* Merge Dispose logic

Also implement IDisposable on SqlMetaDataFactory

* Merge DataTable population method

* Merge ExecuteCommand population method

* Merge top-level GetSchema method

* Merge SupportedByCurrentVersion and properties, remove now-unused base class methods

* Replace unnecessary private properties with variables

* Remove DbMetaDataFactory

Author: edwardneal

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -209,9 +209,6 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\ProviderBase\DbConnectionInternal.cs">
       <Link>Microsoft\Data\ProviderBase\DbConnectionInternal.cs</Link>
     </Compile>
-    <Compile Include="$(CommonSourceRoot)Microsoft\Data\ProviderBase\DbMetaDataFactory.cs">
-      <Link>Microsoft\Data\ProviderBase\DbMetaDataFactory.cs</Link>
-    </Compile>
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\ProviderBase\DbReferenceCollection.cs">
       <Link>Microsoft\Data\ProviderBase\DbReferenceCollection.cs</Link>
     </Compile>

src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj

@@ -282,9 +282,6 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\ProviderBase\DbConnectionInternal.cs">
       <Link>Microsoft\Data\ProviderBase\DbConnectionInternal.cs</Link>
     </Compile>
-    <Compile Include="$(CommonSourceRoot)Microsoft\Data\ProviderBase\DbMetaDataFactory.cs">
-      <Link>Microsoft\Data\ProviderBase\DbMetaDataFactory.cs</Link>
-    </Compile>
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\ProviderBase\DbReferenceCollection.cs">
       <Link>Microsoft\Data\ProviderBase\DbReferenceCollection.cs</Link>
     </Compile>

src/Microsoft.Data.SqlClient/src/Microsoft/Data/Common/AdapterUtil.cs

@@ -1129,9 +1129,6 @@ internal static IndexOutOfRangeException InvalidBufferSizeOrIndex(int numBytes,
         internal static Exception InvalidDataLength(long length)
             => IndexOutOfRange(StringsHelper.GetString(Strings.SQL_InvalidDataLength, length.ToString(CultureInfo.InvariantCulture)));
 
-        internal static bool CompareInsensitiveInvariant(string strvalue, string strconst)
-            => 0 == CultureInfo.InvariantCulture.CompareInfo.Compare(strvalue, strconst, CompareOptions.IgnoreCase);
-
         internal static void SetCurrentTransaction(Transaction transaction) => Transaction.Current = transaction;
 
         internal static Exception NonSeqByteAccess(long badIndex, long currIndex, string method)
@@ -1142,9 +1139,6 @@ internal static Exception NonSeqByteAccess(long badIndex, long currIndex, string
 
         internal static Exception NegativeParameter(string parameterName) => InvalidOperation(StringsHelper.GetString(Strings.ADP_NegativeParameter, parameterName));
 
-        internal static Exception InvalidXmlMissingColumn(string collectionName, string columnName)
-            => Argument(StringsHelper.GetString(Strings.MDF_InvalidXmlMissingColumn, collectionName, columnName));
-
         internal static InvalidOperationException AsyncOperationPending() => InvalidOperation(StringsHelper.GetString(Strings.ADP_PendingAsyncOperation));
 #endregion
 
@@ -1231,7 +1225,7 @@ internal static Exception InvalidCommandTimeout(int value, [CallerMemberName] st
             => Argument(StringsHelper.GetString(Strings.ADP_InvalidCommandTimeout, value.ToString(CultureInfo.InvariantCulture)), property);
 #endregion
 
-#region DbMetaDataFactory
+#region SqlMetaDataFactory
         internal static Exception DataTableDoesNotExist(string collectionName)
             => Argument(StringsHelper.GetString(Strings.MDF_DataTableDoesNotExist, collectionName));
 
@@ -1268,8 +1262,6 @@ internal static InvalidOperationException OpenConnectionRequired(string method,
         internal static Exception OpenReaderExists(Exception e, bool marsOn)
             => InvalidOperation(StringsHelper.GetString(Strings.ADP_OpenReaderExists, marsOn ? ADP.Command : ADP.Connection), e);
 
-        internal static Exception InvalidXml() => Argument(StringsHelper.GetString(Strings.MDF_InvalidXml));
-
         internal static Exception InvalidXmlInvalidValue(string collectionName, string columnName)
             => Argument(StringsHelper.GetString(Strings.MDF_InvalidXmlInvalidValue, collectionName, columnName));
 
@@ -1287,8 +1279,6 @@ internal static Exception UndefinedCollection(string collectionName)
         internal static Exception AmbiguousCollectionName(string collectionName)
             => Argument(StringsHelper.GetString(Strings.MDF_AmbiguousCollectionName, collectionName));
 
-        internal static Exception MissingRestrictionColumn() => Argument(StringsHelper.GetString(Strings.MDF_MissingRestrictionColumn));
-
         internal static Exception MissingRestrictionRow() => Argument(StringsHelper.GetString(Strings.MDF_MissingRestrictionRow));
 
         internal static Exception UndefinedPopulationMechanism(string populationMechanism)

src/Microsoft.Data.SqlClient/src/Microsoft/Data/ProviderBase/DbConnectionInternal.cs

@@ -860,7 +860,7 @@ protected internal virtual DataTable GetSchema(
         {
             Debug.Assert(outerConnection is not null, "outerConnection may not be null.");
 
-            DbMetaDataFactory metaDataFactory = factory.GetMetaDataFactory(poolGroup, this);
+            SqlMetaDataFactory metaDataFactory = factory.GetMetaDataFactory(poolGroup, this);
             Debug.Assert(metaDataFactory is not null, "metaDataFactory may not be null.");
 
             return metaDataFactory.GetSchema(outerConnection, collectionName, restrictions);