Provide adequate exception messages on IdentityServer profiles misconfiguration

### Is your feature request related to a problem? Please describe.
This is a continuation of #16916 and #20248. I opened new issue because I can't re-open the original ones.

Context: https://github.com/dotnet/aspnetcore/issues/20248#issuecomment-619787938

### Describe the solution you'd like
It would be nice to have something like `Type 'API' should be configured in 'Resources' section not 'Clients'` instead of current `Type 'API' is not supported.`

Current exception message along with the documentation wording (where all profiles listed together in one list) is very misleading especially for beginners.