ref(plugins): Minor fixes for plugins

[leeandher]

This PR is a variety of small edits while investigating plugin webhooks.

• Typing on the middleware
• Removing unused features from GitLab listing
• Add logging to check for dead code on Github/Bitbucket (which I suspect were migrated)
• Rename Plugin views to avoid naming collision with integration views

[codecov]

Codecov Report

Merging #54217 (9a71c09) into master (c0e47b1) will increase coverage by 0.02%.
Report is 55 commits behind head on master.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #54217      +/-   ##
==========================================
+ Coverage   79.60%   79.63%   +0.02%     
==========================================
  Files        4989     4982       -7     
  Lines      210817   211110     +293     
  Branches    35908    35962      +54     
==========================================
+ Hits       167830   168107     +277     
- Misses      37831    37837       +6     
- Partials     5156     5166      +10     

Files Changed	Coverage Δ
...try/middleware/integrations/integration_control.py	100.00% <100.00%> (ø)

... and 56 files with indirect coverage changes