[New Feature]: Add ".validation" files to packages whose domains trigger "Validation-Domain" despite being the same domains as in earlier package versions.

### Description of the new feature/enhancement

From time to time recently, package updates trigger `Validation-Domain`, which is essentially a death sentence due to:
* #333858.

Despite that earlier versions of the same package had the exact same domains approved and/or waived. Thus the process to *de facto* appeal the death sentence needs to get sped up and probably automated under such circumstances.

Instances at the time of writing include, but are not necessarily limited to:
* #375315
* #376245
* #379200
* #379298
* #381053
* #381102
* #381337
* #382911

### Proposed technical implementation details (optional)

If a PR meets all of the following:
* Has either the `Validation-Domain` or `Validation-Unapproved-URL` labels.
* Has the `New-Manifest` label.
* Does not have any actual breaker labels, such as `Needs-CLI`, `Manifest-Validation-Error`, `Validation-404-Error`, `Errоr-Hаsh-Mіsmаtch`, `Validation-Unattended-Failed`, or `Validation-Installation-Error`.

Then a `.validation` file is automatically added to the package, which serves to automatically waive `Validation-Domain` and `Validation-Unapproved-URL` for the specific domain that was in the previous version of the package.

No files, tests, or entry points are named. Start by reviewing #333858 and the listed package issues, then trace how Validation-Domain, Validation-Unapproved-URL, New-Manifest, and breaker labels are processed. Done means qualifying updates automatically receive a .validation file that waives only the previously approved domain checks.

Written by the indexing model from the issue text.