KapuaCofigurableService cleanup and added a bunch of javadoc

[Coduz]

This PR add a bunch of javadoc to the KapuaConfigurableService stuff and cleans up a bit the code

Related Issue None

Description of the solution adopted Added a bunch of documentation and removed not used stuff

Screenshots None

Any side note on the changes made None

[codecov[bot]]

Codecov Report

Merging #3571 (a188327) into develop (d1df80d) will decrease coverage by 28.87%. The diff coverage is 49.13%.

:exclamation: Current head a188327 differs from pull request most recent head f475657. Consider uploading reports for the commit f475657 to get more accurate results

@@              Coverage Diff               @@
##             develop    #3571       +/-   ##
==============================================
- Coverage      50.22%   21.35%   -28.88%     
+ Complexity       259       72      -187     
==============================================
  Files           1662     1668        +6     
  Lines          31946    31992       +46     
  Branches        2643     2637        -6     
==============================================
- Hits           16046     6833     -9213     
- Misses         14964    24561     +9597     
+ Partials         936      598      -338     

Impacted Files	Coverage Δ
...uration/exception/KapuaConfigurationException.java	37.50% <ø> (ø)
...viceConfigurationParentLimitExceededException.java	0.00% <0.00%> (ø)
...pper/ServiceConfigurationLimitExceptionMapper.java	0.00% <0.00%> (ø)
...erviceConfigurationParentLimitExceptionMapper.java	0.00% <0.00%> (ø)
...erviceConfigurationLimitExceededExceptionInfo.java	0.00% <0.00%> (ø)
...ConfigurationParentLimitExceededExceptionInfo.java	0.00% <0.00%> (ø)
...eclipse/kapua/app/api/web/JaxbContextResolver.java	0.00% <ø> (-77.78%)	:arrow_down:
...cation/credential/shiro/CredentialServiceImpl.java	30.80% <0.00%> (-5.69%)	:arrow_down:
...e/kapua/service/user/internal/UserServiceImpl.java	21.64% <25.00%> (-28.73%)	:arrow_down:
...on/ServiceConfigurationLimitExceededException.java	50.00% <50.00%> (ø)
... and 637 more