feat(findings): add /findings/metadata to retrieve dynamic filters information

[prowler-bot]

Backport

This will backport the following commits from master to v5.1:

• feat(findings): add /findings/metadata to retrieve dynamic filters information (#6503)

Questions ?

Please refer to the Backport tool documentation

[jfagoagas]

We are going to release 5.2.0, but it is needed to fix 5.1.2.

[codecov]

Codecov Report

Attention: Patch coverage is 95.74468% with 2 lines in your changes missing coverage. Please review.

Project coverage is 93.68%. Comparing base (bdcba9c) to head (366ffcd).
Report is 5 commits behind head on v5.1.

Additional details and impacted files

@@            Coverage Diff             @@
##             v5.1    #6586      +/-   ##
==========================================
+ Coverage   90.06%   93.68%   +3.62%     
==========================================
  Files        1182       65    -1117     
  Lines       36085     6304   -29781     
==========================================
- Hits        32500     5906   -26594     
+ Misses       3585      398    -3187     

Flag	Coverage Δ
api	93.68% <95.74%> (?)
prowler	?

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Components	Coverage Δ
prowler	∅ <ø> (∅)
api	93.68% <95.74%> (∅)