Add CalH5 file format

[bhazelton]

Description

Add support for a new HDF5 based UVCal file format, with partial read support.

This includes significant refactoring to allow code to be reused, including:

• Refactoring the select method on UVCal (along the lines of the refactored UVData select).
• Refactoring a lot of the HDF5 code from uvh5.py into a new hdf5_utils.py file at the top level.
• Refactoring time selection logic from UVData, moving it into utils.py.

Motivation and Context

addresses #876

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation change (documentation changes only)
• Version change
• Build or continuous integration change

Checklist:

• I have read the contribution guide.
• My code follows the code style of this project.

New feature checklist:

• I have added or updated the docstrings associated with my feature using the numpy docstring format.
• I have updated the tutorial to highlight my new feature (if appropriate).
• I have added tests to cover my new feature.
• All new and existing tests pass.
• I have updated the CHANGELOG.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.92%. Comparing base (05f6a0c) to head (07d9f7a).

Additional details and impacted files

@@             Coverage Diff             @@
##           prep_v3.0    #1362    +/-   ##
===========================================
  Coverage      99.92%   99.92%            
===========================================
  Files             37       39     +2     
  Lines          21093    21488   +395     
===========================================
+ Hits           21077    21472   +395     
  Misses            16       16            

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[kartographer]

@bhazelton -- finally got a chance to look through everything following having had a chance to play around with things. Mostly very minor comments and some questions that may be more a reflection of my lack of prior experience w/ UVCal (always more to learn 😄 ).

[bhazelton]

Tests are breaking because they're picking up the new version of lunarsky. They'll be fixed when we merge #1417 and rebase.

[kartographer]

Looks good, thanks @bhazelton!