Fix LT-22611: Allow Bulk Edit Inflection Features for affixes

[jtmaxwell3]

This fixes https://jira.sil.org/browse/LT-22611. We can't just set the inflection features of the MSA since it may be shared with other lexical senses. So we make a copy of the MSA and set its inflection features. We then see whether there is an existing MSA that matches it. If there is, then we use it and delete the copy.

I added code for deleting newFsTarget if it was created by FillInBlanks and it isn't used elsewhere.

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This change is 

[github-actions]

NUnit Tests

    1 files  ±0      1 suites  ±0   10m 13s ⏱️ -35s
4 306 tests ±0  4 233 ✅ ±0  73 💤 ±0  0 ❌ ±0 
4 315 runs  ±0  4 242 ✅ ±0  73 💤 ±0  0 ❌ ±0 

Results for commit 907f070. ± Comparison against base commit 9b7d537.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 41 lines in your changes missing coverage. Please review.
✅ Project coverage is 32.98%. Comparing base (b30d631) to head (907f070).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
Src/FdoUi/InflectionFeatureEditor.cs	0.00%	32 Missing and 9 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1018      +/-   ##
==========================================
- Coverage   32.99%   32.98%   -0.01%     
==========================================
  Files        1202     1202              
  Lines      278175   278248      +73     
  Branches    37152    37169      +17     
==========================================
+ Hits        91781    91788       +7     
- Misses     158543   158593      +50     
- Partials    27851    27867      +16     

Files with missing lines	Coverage Δ
Src/FdoUi/InflectionFeatureEditor.cs	0.00% <0.00%> (ø)

... and 3 files with indirect coverage changes

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[mark-sil]

@mark-sil reviewed 1 file and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on jtmaxwell3).