feat: Add timestamp expressions

[yvonnep165]

Add new timestamp expressions timestamp_diff and timestamp_extract and integration tests for the expressions

The expression timestamp_trunc already existed in the repo with integration tests.
Add methods for timestampTruncWithTimezone to avoid signature collision.
Add methods to allow timezone as parameter in chained expressions.
Amend the tests for the timestamp_trunc expression

Ported from firebase/firebase-js-sdk#9728

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📝 PRs merging into main branch

Our main branch should always be in a releasable state. If you are working on a larger change, or if you don't want this change to see the light of the day just yet, consider using a feature branch first, and only merge into the main branch when the code complete and ready to be released.

[yvonnep165]

@rlazo Just for a headsup, we got a Metalava SemVer breaking change alert for timestampTruncate expression porting. But since we're still in public preview, it shouldn't be a problem.

[rlazo]

@rlazo Just for a headsup, we got a Metalava SemVer breaking change alert for timestampTruncate expression porting. But since we're still in public preview, it shouldn't be a problem.

SGTM