Guid validation

[Joshua-Donovan]

Re-adding to pull request list after accidentally deleting this one.

New workflow step to validate the policy definition GUID/UUID and checks for conflicts with existing Built-In Policy Definition names.

Updates since last Pull Request:

• Added a check for if the file is in the "Scripts/" or ".github/workflows" directories. If so, the result will be successful and have an exempt directory message.

Requirements:

• secrets.GH_SEARCH_TOKEN
• Requires a GitHub PAT to authenticate with GitHub search API.
• PAT does not need any permissions, it just needs to be a valid GitHub PAT.

[aschabus]

@Joshua-Donovan wouldn't it be possible to check the GUID against https://www.azadvertizer.net/azpolicyadvertizer-comma.csv for uniqueness. In this case we wouldn't need any permissions or access tokens. The csv file is updated daily against Azure (built-in), ALZ, AMBA and Community Policies.

[Joshua-Donovan]

@Joshua-Donovan wouldn't it be possible to check the GUID against https://www.azadvertizer.net/azpolicyadvertizer-comma.csv for uniqueness. In this case we wouldn't need any permissions or access tokens. The csv file is updated daily against Azure (built-in), ALZ, AMBA and Community Policies.

@aschabus I can play with that possibility, but that does add a dependency on an external resource that using the GitHub search functionality does not.