Customize access token header in OIDC for API

[antoniomacri]

Description
Support changing the header which carries the access token in the OIDC extension for protecting service applications.
Something like smallrye.jwt.token.header (except for "Cookie" value).

I'm having some problems trying to integrate with an API gateway which does not support sending the token as "Authorization: Bearer". It instead would allow sending the token as a plain header, such as:

MyAuthorization: <access_token>