[frontend] Widgets code refacto

[Archidoit]

Proposed changes

Refacto of the widgets code to make it more readable and reusable for the future fintel template widget logic

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 65.38%. Comparing base (c421910) to head (c1cf018).
Report is 3 commits behind head on release/6.5.0.

Additional details and impacted files

@@              Coverage Diff               @@
##           release/6.5.0    #9483   +/-   ##
==============================================
  Coverage          65.38%   65.38%           
==============================================
  Files                626      626           
  Lines              60156    60166   +10     
  Branches            6771     6777    +6     
==============================================
+ Hits               39334    39342    +8     
- Misses             20822    20824    +2     

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[aHenryJard]

Note: might need updates depending on which PR is merged first with #9194