Retrieve tenant-specific OAuth 2.0 Authorization Server Metadata

Returns the Authorization Server configuration metadata for the given tenant in accordance with RFC 8414. Depending on the 'Accept' header, the response is provided either as an unsigned JSON document or as a signed JWT. The metadata includes issuer information, endpoint URLs (e.g., token endpoint), supported grant types and extensions required for OpenID for Verifiable Credential Issuance (OID4VCI) and DPoP.