Enable enum equality predicate pushdown for ClickHouse connector

[sylph-eu]

Description

Partially addresses #7100 .

Enables equality predicate pushdown for enum types. It's similar to VARCHAR (from Trino's perspective), but is not that "general-purpose". Until ClickHouse fully supports collation (atm it's only implemented for ORDER BY clause) range predicates are not pushed down.

Additional context and related issues

Submitted https://github.com/ClickHouse/ClickHouse/issues/62701 for unexpected behaviour.

Next I'll be looking at Decimals, time types and aggregate functions.

Release notes

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# Section
* Enable enum equality predicate pushdown. ({issue}`7100`)

[sylph-eu]

Rebased.

[github-actions[bot]]

This pull request has gone a while without any activity. Tagging the Trino developer relations team: @bitsondatadev @colebow @mosabua

[github-actions[bot]]

This pull request has gone a while without any activity. Tagging the Trino developer relations team: @bitsondatadev @colebow @mosabua

[github-actions[bot]]

Closing this pull request, as it has been stale for six weeks. Feel free to re-open at any time.

[mosabua]

Feel free to reopen and rebase or start a new PR if you want to continue working on this PR @sylph-eu