Add new URLs for SP-only or IDP-only SAML metadata
This commit adds two new URLs:
/saml/metadata/idp : IDP-only metadata
/saml/metadata/sp : SP-only metadata
/saml/metadata keeps providing metadata for all SAML services
I'm expecting this to be useful in cases like #1549 (closed)
!60 (merged) contains the code that will actually let a user have a different EntityID for the IDP and SP, making this PR much more relevant.