Consider letting redirect url respect response_mode after receiving invalid request on authorization endpoint

[RolandGuijt]

AuthorizeRequestValidator in the ValidateCoreParameters method only applies the received response_mode (e.g. "fragment") to the redirect url after checking for grant type and PKCE errors. When such errors occurs it returns from the method too early.

See issue DuendeSoftware/Support#1238

Considerations around this:

• Fixing it will be a breaking change
• The mentioned error types are unsafe errors that should result in displaying an error page. The redirect url isn't supposed to be used.
• But, when getting the error context we do have access to the redirect url which now always uses the "query" formatting because that is the default.