Regression: Show mention instead of the name of the user in app request messages

[rique223]

Proposed changes (including videos or screenshots)

Jira task: MKP-249

Stopped using the name of users that requested apps and now the app request messages directly mention the users.
Demo image:

Issue(s)

Steps to test or reproduce

1. Request an app in an account that doesn't have manage-app permission;
2. Logout of that account and login into an account that has manage-app permission;
3. Click on the rocket.cat message;

Further comments

[codecov]

Codecov Report

Merging #28200 (912a01a) into develop (29f3f72) will decrease coverage by 0.37%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop   #28200      +/-   ##
===========================================
- Coverage    44.87%   44.50%   -0.37%     
===========================================
  Files          766      748      -18     
  Lines        14936    14615     -321     
  Branches      2079     2072       -7     
===========================================
- Hits          6702     6504     -198     
+ Misses        7941     7815     -126     
- Partials       293      296       +3     

Flag	Coverage Δ
e2e	44.47% <ø> (-0.36%)	⬇️

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[ggazzo]

did you try create a mention instead? just the raw username is not much better the name