Add privateAttributes to global and per model response

[dalbitresb12]

Description of what you did:

Restarting the work made from PR's #6002 and #4914. Also added the option to ignore the global private attributes per model using options.ignoreGlobalPrivateAttributes. Finally, new tests were added for sanitizeEntity.

Fixes #4342.

[codecov]

Codecov Report

Merging #7330 into master will increase coverage by 0.07%.
The diff coverage is 51.28%.

@@            Coverage Diff             @@
##           master    #7330      +/-   ##
==========================================
+ Coverage   26.17%   26.24%   +0.07%     
==========================================
  Files        1130     1131       +1     
  Lines       15415    15434      +19     
  Branches     2439     2443       +4     
==========================================
+ Hits         4035     4051      +16     
- Misses       9561     9563       +2     
- Partials     1819     1820       +1     

Flag	Coverage Δ
#front	18.26% <0.00%> (-0.01%)	⬇️
#unit	53.21% <100.00%> (+0.24%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...s/strapi-admin/admin/src/containers/Admin/index.js	63.82% <ø> (ø)
...admin/admin/src/containers/Roles/EditPage/index.js	2.77% <0.00%> (-0.80%)	⬇️
...admin/admin/src/containers/Roles/ListPage/index.js	0.00% <0.00%> (ø)
...ermissions/admin/src/components/PopUpForm/index.js	0.00% <0.00%> (ø)
packages/strapi-admin/services/metrics.js	100.00% <100.00%> (ø)
packages/strapi-admin/services/role.js	94.11% <100.00%> (+0.14%)	⬆️
packages/strapi-admin/services/user.js	82.56% <100.00%> (+0.66%)	⬆️
packages/strapi-utils/lib/sanitize-entity.js	65.07% <100.00%> (+3.78%)	⬆️
packages/strapi/lib/services/metrics/sender.js	100.00% <100.00%> (ø)
... and 1 more

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[dalbitresb12]

Sorry, I forgot to sign for DCO. Force-pushing didn't seem to work, so I opened a new PR: #7331.