JP-3518: Match imprint and science association members by mosaic and dither position

[tapastro]

Resolves JP-3518

Closes #8215

This PR addresses mismatches between NIRSpec science and imprint members in level2 spectral associations.

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.78%. Comparing base (2fb073e) to head (0abd5fa).
Report is 23 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8410      +/-   ##
==========================================
+ Coverage   75.31%   75.78%   +0.47%     
==========================================
  Files         474      476       +2     
  Lines       38965    39450     +485     
==========================================
+ Hits        29345    29897     +552     
+ Misses       9620     9553      -67     

Flag	Coverage Δ		*Carryforward flag
nightly	77.65% <ø> (+0.31%)	⬆️	Carriedforward from 2fb073e

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[hbushouse]

@tapastro Is this ready for review? If so, can you un-draft it?

[tapastro]

Apologies, meant to un-draft this after our planning meeting but it ran into my departure for a doctor's appt.

Regtests here: https://plwishmaster.stsci.edu:8081/job/RT/job/JWST-Developers-Pull-Requests/1374/

The new pool I added is an expected failure, but results have been verified locally.

[hbushouse]

Code looks good, regtests look good.