Changes for handling org level rulesets

[decyjphr]

Rulesets are now available in GitHub. These changes are to support configuring Rulesets using safe-settings.

Approach

We will support org level rulesets using -rulesets: entries in .github/settings.yml and repo level rulesets using -rulesets: entries in the .github/repos/<repo>.yml (deferring the handling of rulesets entries in <suborg>.yml until ruleset targeting using repo properties is available and we would want to do the same in suborg yml)

[decyjphr]

Added 2 env variables to control messages during errors or during the PR checkrun.

Env variable	default	behavior
CREATE_PR_COMMENT	true	Will show the differences in the PR comments between the existing config and the new changes being applied in the PR body
CREATE_ERROR_ISSUE	true	Will create an issue in the admin repo when there are errors when applying the settings. So the errors don't happen silently

Instead of this approach of creating an issue for showing the errors when safe-settings runs, I've made changes so a check is created for the latest commit. If there are errors the check shows as failure.

Previously when there were errors when applying safe-settings, or if the custom-validators return false, it is not visible to the users, with this approach, the checkrun details will show the errors when they occur.