fix: Check for missing identities on migration 36

[Cal-L]

Description

This PR adds a check for ensuring that identities are defined under PreferencesController for migration 36.
More context here - #9080

Related issues

Fixes:

Manual testing steps

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Screenshots/Recordings

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[github-actions]

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 45.55%. Comparing base (3c0ac7d) to head (8ad5f12).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9082      +/-   ##
==========================================
- Coverage   45.55%   45.55%   -0.01%     
==========================================
  Files        1272     1272              
  Lines       31235    31238       +3     
  Branches     3188     3189       +1     
==========================================
+ Hits        14230    14231       +1     
- Misses      16167    16168       +1     
- Partials      838      839       +1     

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