feat(optimizer)!: annotate compress for mysql

[PiyaDaswadkar]

This PR annotate the function Compress for mysql

https://dev.mysql.com/doc/refman/9.7/en/encryption-functions.html#function_compress

[PiyaDaswadkar]

One thing I'm unsure about is the implementation: the existing generic type groups don't seem to match the COMPRESS() mapping exactly (for example, TEXT_TYPES includes CHAR, VARCHAR, and TINYTEXT, which have different output types here). Would you prefer that I add new reusable groups in datatypes.py, or should I list the types explicitly in _annotate_compress?

[geooo109]

@PiyaDaswadkar let's create sets in the mysql typing file.

[PiyaDaswadkar]

Updated the COMPRESS annotation based on the MySQL type mappings you provided. I added dedicated input type sets in mysql.py and moved COMPRESS from the fixed return type mapping to a custom annotator. Also added fixture coverage for LONGBLOB, BLOB, and VARBINARY output cases.

[PiyaDaswadkar]

Done, I updated the implementation to reuse TEXT_TYPES where appropriate and removed the unnecessary single-type set. I also updated the tests accordingly.

[geooo109]

@PiyaDaswadkar I will take this PR to the finish line, thanks!