Pull-request numbers in subdomain

**Is your feature request related to a problem? Please describe.**

My pull-requests are deployed to a domain like this:
`https://cool-cat-00abcdef-22.westeurope.azurestaticapps.net/`

To allow for the pull-request domains to connect to backend services we need to both wildard CORS, and wildcard redirect URIs to our in-app OAuth2 MSAL. Today both need wildcards on the `*.westeurope.azurestaticapps.net/` allowing all apps on SWA to connect to my services and use my OAUTH. Neither CORS or OAUTH allows wildcards in arbitrary places in an URL, they just allow subdomain wildcards.

**Describe the solution you'd like**

I would like the pull-request domains to be formatted like this: `https://22.cool-cat-00abcdef.westeurope.azurestaticapps.net/`. Where `22` is the current pull-request id. This way I could wildcard a subdomain of my assigned name, and have some kind of safety. `https://*.cool-cat-00abcdef.westeurope.azurestaticapps.net`

**Describe alternatives you've considered**

* Wildcard both CORS and redirect URI. (As described above this allows any app to use the same OAUTH)
* Script setup of CORS and redirect URI in the build. This requires much effort, and teardown is cumbersome.
* Pre-allocate urls for the next 100 pull-requests. (Its not stupid if it works?)