[CALCITE-6392] Support all PostgreSQL 14 date/time patterns for to_date/to_timestamp

[normanj-bitquill]

This is layered on top of https://github.com/apache/calcite/pull/3773

• First phase, mostly reorganizing classes
• Does not yet implement to_date or to_timestamp
• Fixed up fill mode handling
• Isolated the unit test class so that it can make Locale changes safely
• Introduced some new classes split out handling of some formats strings

There will be subsequent PRs to further implement to_date and to_timestamp for PostgreSQL.

[sonarqubecloud[bot]]

Quality Gate passed

Issues
13 New issues
0 Accepted issues

Measures
0 Security Hotspots
85.6% Coverage on New Code
7.0% Duplication on New Code

See analysis details on SonarCloud

[mihaibudiu]

oops, I merged the wrong PR

[mihaibudiu]

I have reverted these 6 commits merged by mistake in main. Can you please resubmit these as a separate PR? It looks like a merged PR cannot be reopened.