Add CODEOWNERS linter baseline error file (Azure#27960)

CODEOWNERS is now going to be linted. _This PR contains the existing
linter errors, deduped, which are used to filter results, otherwise this
pipeline couldn't be run on PRs that contain CODEOWNERS changes without
the several hundred issues being fixed, which is not ideal._ The linter
will run daily and on every change to CODEOWNERS or the baseline file.
Specific details of the linting can be found
[here](https://github.com/Azure/azure-sdk-tools/tree/main/tools/codeowners-utils#linting)
but here is what's being verified in a nutshell.

- Metadata tags - PRLabels, ServiceLabels, ServiceOwners (previously
/<NotInRepo>/, both are still valid for the moment) and
AzureSdkOwners (new, used for issue triage).
- Source paths - Does the path exist? If the path is a glob, is it valid
and does it have matches in the repository?
- Owners - There are several verifications for owners:
- Does the owner, individual or team, have write access (every
team/individual in a CODEOWNERS file needs to have write access, this is
a GitHub thing).
- Is the owner public? Individuals need to set their Azure membership to
public. This is explicitly mentioned in the [onboarding
documents](https://eng.ms/docs/products/azure-developer-experience/onboard/access)
for azure-sdk repositories.