JP-4144: Update number of characters in SUBARRAY and READPATT table entries

[drlaw1558]

Partially resolves JP-4144 by increasing the number of characters available to the SUBARRAY keyword for various data models.

Tasks

• update or add relevant tests
• update relevant docstrings and / or docs/ page
• Does this PR change any API used downstream? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types)
  • run jwst regression tests with this branch installed ("git+https://github.com/<fork>/stdatamodels@<branch>")

news fragment change types...

• changes/<PR#>.feature.rst: new feature
• changes/<PR#>.bugfix.rst: fixes an issue
• changes/<PR#>.doc.rst: documentation change
• changes/<PR#>.removal.rst: deprecation or removal of public API
• changes/<PR#>.misc.rst: infrastructure or miscellaneous change

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.66%. Comparing base (904f3c1) to head (7437112).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #759   +/-   ##
=======================================
  Coverage   90.66%   90.66%           
=======================================
  Files          99       99           
  Lines        4619     4619           
=======================================
  Hits         4188     4188           
  Misses        431      431           

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[drlaw1558]

Tagging @jemorrison

[jemorrison]

@drlaw1558 Please remove the rscd ones. They have been tested/ review and I have run regression test.
They are in #758

[drlaw1558]

@jemorrison Done

[tapastro]

Changes look reasonable enough, though the description mentions READPATT changes - I don't see any of those here. Were they dropped accidentally from the PR, or should that be removed from the changelog fragment?

[tapastro]

RTs: https://github.com/spacetelescope/RegressionTests/actions/runs/27422307750

[drlaw1558]

READPATT used to be in here too, but that got dropped so as not to step on @jemorrison 's other PR. I've updated the description.