refactor: Remove unused headers and gflags

[majetideepak]

Remove unused headers in velox/common/base/VeloxException.h

This is required for the dynamic library PR to remove dependency on GLOG
#11439 (comment)

[netlify]

✅ Deploy Preview for meta-velox canceled.

Name	Link
🔨 Latest commit	6489e7f
🔍 Latest deploy log	https://app.netlify.com/sites/meta-velox/deploys/67a269dff0f36300081c116b

[mohsaka]

@majetideepak

Seems like a reliance on glog on velox/common/base/Exceptions.h which resolved its dependency through velox/common/base/VeloxException.h is causing some failures.

[majetideepak]

@mohsaka There are a couple of such issues. I am fixing them locally.

[majetideepak]

@kgpai this is ready for review. Can you please take a look? Thanks.

[mohsaka]

@majetideepak Attempted to build the code with the dynamic library PR but the dependency was moved to Exceptions.h.

The include tree seems to be
Udf.h -> Macros.h -> Type.h -> Exceptions.h
-> SimpleFunctionApi.h -> CppToType.h -> Type.h -> Exceptions.h
-> Registerer.h -> SimpleFunctionMetadata.h -> Exceptions.h
-> Registerer.h -> SimpleFunctionMetadata.h -> ***** -> Exceptions.h
-> Registerer.h -> SimpleFunctionAdapter -> Vector stuff -> Exceptions.h

Macros.h needed for VELOX_DEFINE_FUNCTION_TYPES
Registerer.h needed for registerFunction

[majetideepak]

@mohsaka thanks for the update! This cleanup is required anyway.

the dependency was moved to Exceptions.h.

I will take a look at this further.