Fix popup window name to element id transform

[stefanw]

Description

Django 4.1 adds a popup index to the admin popup window name that needs to be stripped when getting back to the element id.

This should be backwards compatible to previous element ids unless they use double underscores (__) in them.

Checklist

• I have opened this pull request against master
• I have added or modified the tests when changing logic
• I have followed the conventional commits guidelines to add meaningful information into the changelog
• I have read the contribution guidelines and I have joined #workgroup-pr-review on
  Slack to find a “pr review buddy” who is going to review my pull request.

[codecov]

Codecov Report

Merging #1326 (26e4895) into master (62551a1) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1326   +/-   ##
=======================================
  Coverage   72.21%   72.21%           
=======================================
  Files          72       72           
  Lines        3239     3239           
  Branches      468      468           
=======================================
  Hits         2339     2339           
  Misses        734      734           
  Partials      166      166           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[fsbraun]

Could that be the root cause of #1317 ?

[stefanw]

Yes, sounds very much like what I experienced.

[fsbraun]

Well spotted!! Thank you!