Adding DateTime part functions

[jdunkerley]

Pull Request Description

• Added Zone, Date_Time and Time_Of_Day to Standard.Base.
• Renamed Zone to Time_Zone.
• Added century.
• Added is_leap_year.
• Added length_of_year.
• Added length_of_month.
• Added quarter.
• Added day_of_year.
• Added Day_Of_Week type and day_of_week function.
• Updated week_of_year to support ISO.

Important Notes

• Had to pass locale to formatter for date/time tests to work on my PC.
• Changed default of week_of_year to use ISO.

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the
  Scala,
  Java,
  and
  Rust
  style guides.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed: Enso GUI was tested when built using BOTH
    ./run ide build and ./run ide watch.

[radeusgd]

I really like the Zone -> Time_Zone rename, I think it's much clearer now.

I don't understand why in many places we roll our own logic instead of relying on available Java utils (which are rather commonly used so I think we can rely on them without adding tons of tests).

Still, I'm not sure Java is prepared for handling dates prior to 1AD very well, which is understandable as most usecases do not care about such dates. Still, I think according to the philosophy of avoiding data corruption at all costs and preferring crashes to data corruption - I think we should consciously throw an exception for operations that we know that would lead to wrong results. So I think we should either add a few tests for BC dates to make sure they work correctly OR throw exceptions saying explicitly that our tool does not support these kinds of dates.