RCAL-853: Give VA scale factor a reasonable default

[stscieisenhamer]

WIP RCAL-853

Main PR: PR#1354

This PR gives the velocity_aberration.scale_facter meta a default working value of 1.0

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)
  • start a romancal regression test with this branch installed ("git+https://github.com/<fork>/roman_datamodels@<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 97.75%. Comparing base (087a60d) to head (759ea7d).
Report is 51 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #396      +/-   ##
==========================================
+ Coverage   97.56%   97.75%   +0.19%     
==========================================
  Files          30       37       +7     
  Lines        2788     3380     +592     
==========================================
+ Hits         2720     3304     +584     
- Misses         68       76       +8     

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[schlafly]

This looks good to me but can you run regtests? I think those all basically pass through the metadata from the L1s and so probably aren't sensitive to this, but if they are we should know about it.