[release/10.0] Always create new small icons for forms

[github-actions]

Backport of #13983 to release/10.0

/cc @JeremyKuhne

Customer Impact

Users setting a Form Icon that matches the current screen small icon size will have their Icon disposed, causing an ObjectDisposedException when using the original Icon. There is no easy workaround.

Testing

Manual testing with user scenario. Regression test.

Risk

Low, now always creating a new Icon instance.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.10578%. Comparing base (d5eebf7) to head (ac2f620).
⚠️ Report is 2 commits behind head on release/10.0.

Additional details and impacted files

@@                  Coverage Diff                   @@
##           release/10.0      #13984         +/-   ##
======================================================
+ Coverage      77.09712%   77.10578%   +0.00865%     
======================================================
  Files              3273        3273                 
  Lines            644932      644940          +8     
  Branches          47692       47692                 
======================================================
+ Hits             497224      497286         +62     
+ Misses           144031      143986         -45     
+ Partials           3677        3668          -9     

Flag	Coverage Δ
Debug	77.10578% <100.00000%> (+0.00865%)	⬆️
integration	18.99113% <75.00000%> (+0.01064%)	⬆️
production	51.92353% <100.00000%> (+0.01825%)	⬆️
test	97.41256% <100.00000%> (+0.00007%)	⬆️
unit	49.33590% <100.00000%> (+0.00919%)	⬆️

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