Add support for future array shapes in UVBeam

[bhazelton]

Description

Add support for future array shapes in UVBeam

Also added testing for a number of uncovered lines of code related to phased_array beams. In the process, I found and fixed a number of bugs related to the handling of phased array beams in various methods. This brings uvbeam.py to 100% test coverage!

Motivation and Context

closes #914

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] 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:

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

New feature checklist:

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

[codecov[bot]]

Codecov Report

Merging #1194 (64800bb) into main (183597b) will increase coverage by 0.02%. The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1194      +/-   ##
==========================================
+ Coverage   99.90%   99.93%   +0.02%     
==========================================
  Files          32       32              
  Lines       17405    17709     +304     
==========================================
+ Hits        17389    17698     +309     
+ Misses         16       11       -5     

Impacted Files	Coverage Δ
pyuvdata/uvbeam/beamfits.py	100.00% <100.00%> (ø)
pyuvdata/uvbeam/cst_beam.py	100.00% <100.00%> (ø)
pyuvdata/uvbeam/mwa_beam.py	100.00% <100.00%> (ø)
pyuvdata/uvbeam/uvbeam.py	100.00% <100.00%> (+0.37%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 183597b...64800bb. Read the comment docs.