Add operator documentation (BETWEEN, LIKE, IN, IS DISTINCT FROM)

[arnaud-lacurie]

Summary

Adds complete documentation for SQL operators: BETWEEN, LIKE, IN, and IS DISTINCT FROM.

Operators documented

• BETWEEN - Range testing with inclusive bounds
• LIKE - Pattern matching with wildcards (%, _) and ESCAPE clause
• IN - Value list membership testing
• IS DISTINCT FROM - NULL-safe equality comparison

Files

• BETWEEN.rst/diagram with comprehensive examples
• LIKE.rst/diagram with wildcard patterns and ESCAPE
• IN.rst/diagram with NULL handling details
• Updated Comparison.rst with IS DISTINCT FROM
• Updated Operators.rst index
• operators-documentation-queries.yamsql test file
• Updated DocumentationQueriesTests.java

[g31pranjal]

This is probably redundant in light of having a file-level supported_version option

[g31pranjal]

It seems all the yamsql files here have that. IIRC, few or all of these operators were there from before 4.3.5.0; in that case, we could remove the clause altogether just to not confuse it for the version the feature became available

[arnaud-lacurie]

Good point, let me address that.

[g31pranjal]

I see that the IS DISTINCT FROM operator is currently placed under Comparison Operators as well as described in its own page. However, the latter is more elaborate. Is this intentional in the sense that there should be a small summary of the operator in the Comparison Operators page?

[arnaud-lacurie]

This is an earlier attempt at documenting IS DISTINCT FROM that I forgot about when writing a proper page. I think this can go away, or link to the page.
Thanks for catching that!