MNT: Deprecate CubeViz, MosViz, and SpecViz

[pllim]

Description

This pull request is to formally deprecate old helper classes with capital V. That includes CubeViz, MosViz, and SpecViz.
This emits deprecation warning and removes them from high-level imports like from jdaviz import CubeViz but the classes are still there for a few more releases.

I think @orifox and @ojustino are both active in JDAT notebooks, so they can confirm whether we can go ahead with this or not.

Fixes #857

After merge

• Open follow-up issue to completely remove the deprecated classes after a few releases. See Remove deprecated CubeViz, MosViz, SpecViz #1815

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

Base: 88.04% // Head: 88.05% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (66b5c46) compared to base (f9e7b39).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1809   +/-   ##
=======================================
  Coverage   88.04%   88.05%           
=======================================
  Files          95       95           
  Lines       10197    10203    +6     
=======================================
+ Hits         8978     8984    +6     
  Misses       1219     1219           

Impacted Files	Coverage Δ
jdaviz/core/helpers.py	70.00% <ø> (ø)
jdaviz/__init__.py	100.00% <100.00%> (ø)
jdaviz/configs/cubeviz/__init__.py	100.00% <100.00%> (ø)
jdaviz/configs/cubeviz/helper.py	98.41% <100.00%> (+0.05%)	⬆️
jdaviz/configs/mosviz/__init__.py	100.00% <100.00%> (ø)
jdaviz/configs/mosviz/helper.py	86.95% <100.00%> (+0.05%)	⬆️
jdaviz/configs/specviz/__init__.py	100.00% <100.00%> (ø)
jdaviz/configs/specviz/helper.py	58.88% <100.00%> (+0.93%)	⬆️

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[rosteen]

It's past time for this, thanks.

[javerbukh]

I agree that @orifox and @JOTOR should probably take a look at this but I'm approving anyway. We've had these classes on the chopping block for a long time now.

[pllim]

I think @camipacifici also said she was going to check... 🤞

[bmorris3]

👋🏻 Later, "V"s.

[camipacifici]

Only two notebooks in jdat_notebooks need updating:

• ifu_optimal
• specviz_notebook_gui_interaction_redshift

I will take care of these.
Approved!

[pllim]

Thanks, all!