Improve singlestore timestamp precision mapping

[RameshByndoor]

Improve singlestore timestamp precision mapping (#11524)

Description

Is this change a fix, improvement, new feature, refactoring, or other?
It's improvement, Avoids making an extra call to database while toColumnMapping is called

Is this a change to the core query engine, a connector, client library, or the SPI interfaces? (be specific)
Change in singlestore-connector, To get the exact precision of time, timestamp and datetime columns

How would you describe this change to a non-technical end user or system administrator?
This increases query performance and removes redundant calls to metadata tables.

Related issues, pull requests, and links

Documentation

(x) No documentation is needed.
( ) Sufficient documentation is included in this PR.
( ) Documentation PR is available with #prnumber.
( ) Documentation issue #issuenumber is filed, and can be handled later.

Release notes

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( ) Release notes entries required with the following suggested text:

[ebyhr]

Thanks! I'm running all tests locally because PR from forked branch doesn't trigger SingleStore CI.
→ All tests passed

[RameshByndoor]

Thanks for the review @ebyhr .

[ebyhr]

Merged, thanks!