Modify OpenID configuration settings to process and allow an `x-kc_idp_hint field`

[MikeNeilson]

Is your feature request related to a problem? Please describe.
CWMS Usage will allow direct CAC loggin as well as Login.gov, thus we need to support multiple OpenID Connect providers

Describe the solution you'd like
Make use of https://swagger.io/docs/specification/v3_0/openapi-extensions/ to allow setting the parameter and use openid connect discover to retrieve the bulk of details.

Describe alternatives you've considered
None

Additional context
All access is still threw already used keycloak instance, this simply alters how we're doign it.

[MikeNeilson]

We may also be able to get the client id in this way.