JP-3616: Fix NIRSpec FS spec3 slit name

[melanieclarke]

Resolves JP-3616

Closes #8469

When NIRSpec fixed slit data is extracted as a SlitModel, take the slit name from the name attribute if possible.

Also adding a couple basic unit tests to exercise the extract1d step for NIRSpec FS and MOS modes, including testing the output slit name.

Checklist for maintainers

• added entry in CHANGES.rst within the relevant release section
• updated or added relevant tests
• updated relevant documentation
• added relevant milestone
• added relevant label(s)
• ran regression tests, post a link to the Jenkins job below.
  How to run regression tests on a PR
• Make sure the JIRA ticket is resolved properly

[melanieclarke]

Regression tests started here:
https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/1429/

[melanieclarke]

Regression tests show expected changes to SLTNAME and extraction parameters for nirspec_fs_spec3. The remaining failures are unrelated.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 57.96%. Comparing base (6580914) to head (7d56e20).
Report is 13 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8470      +/-   ##
==========================================
+ Coverage   56.38%   57.96%   +1.58%     
==========================================
  Files         387      387              
  Lines       38716    38811      +95     
==========================================
+ Hits        21830    22498     +668     
+ Misses      16886    16313     -573     

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[hbushouse]

Updates look pretty straight forward. Curious, I assume this was just affecting the slit name that's somewhere in the datamodel instance of the output 1-D spectrum (for non-primary slits)? And not actually affecting anything with file naming, etc.?

[melanieclarke]

Updates look pretty straight forward. Curious, I assume this was just affecting the slit name that's somewhere in the datamodel instance of the output 1-D spectrum (for non-primary slits)? And not actually affecting anything with file naming, etc.?

Correct - the file naming was correct, but the SLTNAME in the output header and slit.name in the model was wrong. The only other effect was that the wrong name was used for retrieving extraction parameters. The differences between default extraction parameters are pretty minor for the fixed slits.