BUG: Fix Line Profile when NaN exists

[pllim]

Add test that fails on main without this patch.

Description

This pull request is to plot NaN as zero in Imviz Line Profile.

TODO

If there is a way to render NaN as gap in plot instead of as zero, it would be better. See Specviz behavior.

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: 91.79% // Head: 91.80% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (c12f101) compared to base (04a744c).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1951   +/-   ##
=======================================
  Coverage   91.79%   91.80%           
=======================================
  Files         140      140           
  Lines       14951    14965   +14     
=======================================
+ Hits        13724    13738   +14     
  Misses       1227     1227           

Impacted Files	Coverage Δ
...s/imviz/plugins/line_profile_xy/line_profile_xy.py	99.07% <100.00%> (+0.02%)	⬆️
jdaviz/configs/imviz/tests/test_line_profile_xy.py	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[pllim]

@kecnry thinks there is another way where we can render NaN as gap (like in Specviz) instead of forcing it as zero in plot, but I don't know how Specviz does that, so I am turning it back to draft for now.

[pllim]

The internals changed too much since, so this is superseded by #2594