Refactor whitelist from map to standard allow directives

[aledbf]

What this PR does / why we need it:

Changes whitelist from a map to standard allow/deny directives.

After this PR I will add a new validation to the webhook to detect when the user defined a snippet containing the satisfy directive to avoid duplications

[codecov-io]

Codecov Report

Merging #4101 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4101   +/-   ##
=======================================
  Coverage   57.76%   57.76%           
=======================================
  Files          87       87           
  Lines        6459     6459           
=======================================
  Hits         3731     3731           
  Misses       2296     2296           
  Partials      432      432

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[aledbf]

/retest

[ElvinEfendi]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf, ElvinEfendi

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