Fix MWA Efield beam sign

[bhazelton]

Description

We recently came up with a better way to check E-field beam signs. This led me to realize we had a sign flip in the azimuthally aligned response of the MWA beam. I tracked this down as a clear mistake in translating from the mwa_pb repo so I fixed it and added our new test (which fails on main).

I also realized that there was an error in the beam plots in our tutorials sourced by an unexpected (at least to me) default in imshow: the (0,0) element of the image is placed in the upper left rather than the lower left (which was my expectation). This is fixable via the origin keyword, so I set that for all the imshow plots in the tutorials and also improved the labelling of the beam plots to clearly indicate where East and North are.

I also snuck in a couple beam-related docstring fixes I noticed recently.

Motivation and Context

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.

Bug fix checklist:

• My fix includes a new test that breaks as a result of the bug (if possible).
• All new and existing tests pass.
• I have updated the CHANGELOG.

Documentation change checklist:

• Any updated docstrings use the numpy docstring format.
• If this is a significant change to the readme or other docs, I have checked that they are rendered properly on ReadTheDocs. (you may need help to get this branch to build on RTD, just ask!)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.93%. Comparing base (ed71586) to head (d06c6fc).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1510   +/-   ##
=======================================
  Coverage   99.93%   99.93%           
=======================================
  Files          63       63           
  Lines       21849    21849           
=======================================
  Hits        21834    21834           
  Misses         15       15           

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[jpober]

Good catch!

[jpober]

Uh-oh, looks like I took too long and there are now conflicts in the changelog... If you can fix, I'll approve (quickly).

[jpober]

I assume failing on hera_cal shouldn't block a merge?