Change default collapse function to sum

[javerbukh]

Description

This pull request changes the default collapse function in the Specviz viewers to sum, instead of maximum.

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 change log needed? If yes, is it added to CHANGES.rst?
• Is a milestone set?
• After merge, any internal documentations need updating (e.g., JIRA, Innerspace)?

[codecov]

Codecov Report

Merging #1229 (4b1b8db) into main (1d8ef1a) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1229   +/-   ##
=======================================
  Coverage   77.99%   78.00%           
=======================================
  Files          90       90           
  Lines        7185     7187    +2     
=======================================
+ Hits         5604     5606    +2     
  Misses       1581     1581           

Impacted Files	Coverage Δ
jdaviz/configs/specviz/plugins/viewers.py	80.40% <100.00%> (+0.15%)	⬆️

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[kecnry]

the reset_limits won't be needed with glue-viz/glue#2277

[pllim]

Would still be needed for older glue even if the upstream PR is accepted?

[kecnry]

Does what it says it does - changing from sum, deselecting, the reselecting data re-defaults to sum, but I think that is the behavior we want. Might be nice to consider changing the default upstream in glue, but I think this is a good solution for now!

[kecnry]

Is this cubeviz-specific (does it belong under the cubeviz header)?

[pllim]

Yeah, what else is using collapse besides Cubeviz?

[pllim]

I checked -- Just Cubeviz is using Collapse, though changing the default might have other side effects. If we accept them, we need to update the change log accordingly.

[javerbukh]

It's not an API change, bug fix, or new feature as far as I could tell, so I put it in the "other" category. Since the change happens in the Specviz viewer file but is most prominent in Cubeviz, I'm not entirely sure where it goes!

[pllim]

This PR also changes the spectrum shown, not just the default in Collapse plugin. Is this intentional or desirable?

Before this patch

With this patch

[javerbukh]

I believe so, although @larrybradley was the original reporter of this ticket. Is that the correct behavior, Larry?

[larrybradley]

Yes, the default collapse on load should be sum. I reported on behalf of @PatrickOgle.

[pllim]

Thanks!