refactor: fix UI inconsistency all over Helpdesk

[aerodeval]

Improved Sidebar

### Improved Settings Panel

### Empty states fixed Before

After:

Telephony Settings Revamp

Avatar issues - Inconsistent avatar sizes and name not displayed in solo avatar

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 50.80%. Comparing base (82d3751) to head (a7a3bdc).
⚠️ Report is 128 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2969      +/-   ##
===========================================
+ Coverage    49.67%   50.80%   +1.12%     
===========================================
  Files          124      122       -2     
  Lines         5401     5372      -29     
===========================================
+ Hits          2683     2729      +46     
+ Misses        2718     2643      -75     

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