New app.is_tray_item_open_from_name() method

[pllim]

Description

This pull request is to formally implement app.is_tray_item_open_from_name() that is used in Line Analysis but might be more useful in general. I originally wanted to use it for Compass (#1152) but ended up did not, so this is a separate PR now.

Checklist for package maintainer(s)

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• 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? Milestone is only currently required for PRs related to Imviz MVP.
• After merge, any internal documentations need updating (e.g., JIRA, Innerspace)?

[codecov]

Codecov Report

Merging #1151 (0e44f0b) into main (b2e6c8d) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1151      +/-   ##
==========================================
+ Coverage   76.72%   76.73%   +0.01%     
==========================================
  Files          87       87              
  Lines        6655     6658       +3     
==========================================
+ Hits         5106     5109       +3     
  Misses       1549     1549              

Impacted Files	Coverage Δ
jdaviz/app.py	90.07% <100.00%> (+0.09%)	⬆️
...igs/specviz/plugins/line_analysis/line_analysis.py	85.06% <100.00%> (-0.20%)	⬇️

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[kecnry]

Woops, related to #1153... if we still want app-level read-access to this, then we can rebase #1153 on top to call this internally. But #1153 will provide the functionality we need from within the plugins themselves.

[pllim]

Well, if we end up not needing this, then there is no need to get it in. I turned this into draft for now.