feat: Add CreatedAt and UpdatedAt to Ruleset

[ivanmartos]

This PR will expose fields CreatedAt and UpdatedAt for Ruleset

Closes#3315

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[gmlewis]

Thank you, @ivanmartos !
Please run go generate ./... and push (not force-push) the changes to this PR as explained in step 4 of CONTRIBUTING.md.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.05%. Comparing base (2b8c7fa) to head (8f11111).
Report is 143 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3316 +/- ##
==========================================
- Coverage 97.72% 93.05% -4.67% 
==========================================
Files 153 172 +19 Lines 13390 11760 -1630 ==========================================
- Hits 13085 10943 -2142 - Misses 215 723 +508 - Partials 90 94 +4 

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[gmlewis]

Thank you, @ivanmartos !
LGTM.
Merging.