Allow change in cmap_att on change in data components

[bmorris3]

Description

Glue scatter viewers plot 2D scatter points, with an option for custom sizes and colors, mapped onto any of the glue Data's components. In order for this to work correctly, the glue ComponentIDComboHelpers like the cmap_att_helper, which can be found at viewer.layers[0].state.cmap_att_helper, must have a list of choices which are in sync with all of that layer's Data components. If components can be added or renamed, the component choices within PlotOptionsSyncState should be updated. I was using this feature in LCviz today, and I found that those component choices do not get updated (😱).

I traced the problem back to one line, and implemented a fix in this PR. No one will see any difference in jdaviz (until we use more scatter viewers in the near[?] future!), but this PR enables features that are implemented but not working in LCviz.

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 and coverable lines are covered by tests ✅

Comparison is base (dc09c8e) 90.83% compared to head (a5cf663) 90.80%.
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2567      +/-   ##
==========================================
- Coverage   90.83%   90.80%   -0.04%     
==========================================
  Files         160      160              
  Lines       19291    19394     +103     
==========================================
+ Hits        17523    17610      +87     
- Misses       1768     1784      +16     

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