[frontend] Update leftbar items design v7 (#13452)

[esrevi]

Proposed changes

• Redesign left bar items
• Add new component LeftBarItem to handle the menu items
• Refactor LeftBar with that component for better maintainability

Related issues

• Left Navigation Redesign #13452

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case (coverage and e2e)
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[codecov]

Codecov Report

❌ Patch coverage is 0% with 100 lines in your changes missing coverage. Please review.
✅ Project coverage is 2.75%. Comparing base (317eb78) to head (c40b075).
⚠️ Report is 35 commits behind head on release/current.

Files with missing lines	Patch %	Lines
...i-front/src/private/components/nav/LeftBarItem.tsx	0.00%	69 Missing ⚠️
...encti-front/src/private/components/nav/LeftBar.jsx	0.00%	29 Missing ⚠️
...front/src/private/components/nav/LeftBarHeader.tsx	0.00%	2 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##           release/current   #13899      +/-   ##
===================================================
+ Coverage             2.58%    2.75%   +0.17%     
===================================================
  Files                 2127     2137      +10     
  Lines               109368   110461    +1093     
  Branches             29834    30269     +435     
===================================================
+ Hits                  2825     3042     +217     
- Misses              106543   107419     +876     

Flag	Coverage Δ
opencti	2.75% <0.00%> (+0.17%)	⬆️
opencti-front	2.75% <0.00%> (+0.17%)	⬆️

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