PG-Vector support in Babelfish

[KushaalShroff]

Description

With GenAI capturing the imagination and Vector Similarity search being one of the foundational features in this space, we MUST leverage what is being offered by pgvector and make it available for T-SQL applications.
With this commit, users can install the vector extension in SYS schema and start using not only the datatype but also all of the other features available in pgvector extension [https://github.com/pgvector/pgvector].
NOTE: Except for Creation of IVFFLAT and HNSW indexes, rest all queries must follow TSQL syntax and semantics.

TASK: BABEL-4687
Signed-off-by: Kushaal Shroff [email protected]

Check List

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• Overall coverage increased (+0.03%) to 72.464%

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Totals
Change from base Build 7589172844:	0.03%
Covered Lines:	40146
Relevant Lines:	55401

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💛 - Coveralls

[Deepesh125]

2 general questions:

1. Do we need to do anything additional on the top of existing DROP INDEX to support dropping these indexes?
2. What would happen if we try to create indexes with different strategy (HNSW and IVFFLAT) on same columns?