feat: implement resolvers

[chrisimcevoy]

• Ports the following Noda Time delegates to Protocols which describe different types of "resolver":
  • AmbiguousTimeResolver
  • SkippedTimeResolver
  • ZoneLocalMappingResolver
• Implements the Resolvers class which contains commonly-used implementations of the above.

Relates to:

• Provide an example in the quick start section of README.md #232

[codecov]

Codecov Report

Attention: Patch coverage is 88.76404% with 20 lines in your changes missing coverage. Please review.

Project coverage is 95.99%. Comparing base (5590c34) to head (fd7fa2b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
tests/time_zones/test_resolvers.py	90.00%	8 Missing ⚠️
pyoda_time/_zoned_date_time.py	66.66%	4 Missing ⚠️
pyoda_time/time_zones/_zone_local_mapping.py	60.00%	4 Missing ⚠️
pyoda_time/time_zones/_resolvers.py	94.73%	3 Missing ⚠️
pyoda_time/_offset_date_time.py	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #240      +/-   ##
==========================================
+ Coverage   95.96%   95.99%   +0.03%     
==========================================
  Files         256      259       +3     
  Lines       19431    19606     +175     
==========================================
+ Hits        18646    18821     +175     
  Misses        785      785              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.