[Identity] Fix Identity UI asset definitions

[javiercn]

Backport of #55218

• Fix the package definitions for Identity UI as they were wrong and break when compiled against a newer (10.0) SDK.
• Previously, if we didn't find the endpoints for the assets, they would get re-generated on the fly.
• As part of optimizing our build performance we reduce the cases in which that happened.
• As a result, the identity UI endpoints (which were incorrectly defined) no longer are defined on the flight and break.
• This fix corrects the endpoints that are embedded into the package and avoids the need to re-generate them.

[javiercn]

No longer technically needed as it was addressed/worked around on the 10.0 SDK dotnet/sdk#47734. We only want to take it if we want to reduce the work the build does, but it shouldn't be a significant change.

[dotnet-policy-service]

Hi @@javiercn. This PR was just approved to be included in the upcoming servicing release. Somebody from the @dotnet/aspnet-build team will get it merged when the branches are open. Until then, please make sure all the CI checks pass and the PR is reviewed.