BUG: Cubeviz to recognize VLT MUSE data

[pllim]

Description

This pull request is to address the wavelength unit portion of #2502 .

• Extension name is DATA.
• CUNIT3 is AWAV (no E).

With this patch:

Performance issues with large cube still exist and are out of scope here.

Change log entry

• Is a change log needed? If yes, is it added to CHANGES.rst? If you want to avoid merge conflicts,
  list the proposed change log here for review and add to CHANGES.rst before merge. If no, maintainer
  should add a no-changelog-entry-needed label.

Checklist for package maintainer(s)

This checklist is meant to remind the package maintainer(s) who will review this pull request of some common things to look for. This list is not exhaustive.

• Are two approvals required? Branch protection rule does not check for the second approval. If a second approval is not necessary, please apply the trivial label.
• Do the proposed changes actually accomplish desired goals? Also manually run the affected example notebooks, if necessary.
• Do the proposed changes follow the STScI Style Guides?
• Are tests added/updated as required? If so, do they follow the STScI Style Guides?
• Are docs added/updated as required? If so, do they follow the STScI Style Guides?
• Did the CI pass? If not, are the failures related?
• Is a milestone set? Set this to bugfix milestone if this is a bug fix and needs to be released ASAP; otherwise, set this to the next major release milestone.
• After merge, any internal documentations need updating (e.g., JIRA, Innerspace)? 🐱

[codecov]

Codecov Report

All modified lines are covered by tests ✅

Files	Coverage Δ
jdaviz/configs/cubeviz/plugins/parsers.py	83.71% <100.00%> (ø)

📢 Thoughts on this report? Let us know!.

[kecnry]

is there any risk here of this catching something we don't want it to?

[pllim]

I think the risk is pretty small given the values are supposedly defined by WCS standards. Do you want me to cross-check with this?

https://github.com/astropy/astropy/blob/32bd0ffb6898c6a57b9ec1a55c13c7a0efe8d273/astropy/wcs/wcsapi/fitswcs.py#L107

[kecnry]

looks like there are (currently) three possible matches (WAVE, WAVN, AWAV). Do we need any order of preference to these or are there no cases where multiple ones would be present?

[pllim]

Do we need any order of preference to these or are there no cases where multiple ones would be present?

I don't think any sane cube WCS has more than 1 spectral axis at a given time?

If it does, how do we even know which one to use?

[kecnry]

right now it would just be somewhat random.... but no need to make the logic more complicated if that case doesn't exist. Let's leave as-is for now. Thanks!

[javerbukh]

LGTM!

[pllim]

Thanks for the reviews!