Add support for IdP federation-wide attribute mappers

[cgeorgilakis]

I believe that we could develop this extension to Keycloak. Of cource IdentityProvidersMappers type and functionality must not change. My proposal is:

• IdentityProviderMapperEntity has mandatory field identityProviderAlias. This will become optional and optional field samlFederationInternalId will be created for SAML federation attribute mappers.
• SAML Federation mappers will be created in seperate tab in SAML Federation like mappers for SAML Identity provider
• During user authorization ( class IdentityBrokerService) , mappers will be taken from method getIdentityProviderMappersByAliasAndFed(RealmModel realmModel, String brokerAlias, SetfederationIds) instead of getIdentityProviderMappersByAlias(RealmModel realmModel, String brokerAlias). The new method will be return IdentityProvidermappers together with SAML federation mappers if IdentityProvider belong to SAML federation(s) and SAMLFederationMappers exist. getIdentityProviderMappersByAlias will remain same for other uses like for returning in ui IdentityProviderMappers.

[cgeorgilakis]

Mappers like SAML Identity Provider mappers will be created as seperated tab in SAML federation.

Functionalites wanted :

1. Add these mappers to SAML IdP only during creation
2. Button per Mapper addAll for add specific mapper to all SAML federation IdPs ( only check that mapper with same name does not exist in IdP )
3. Button update for update all related SAML IdP mappers (based on name)
4. Button remove for remove all related SAML IdP mappers (based on name)

[cgeorgilakis]

Federation Mappers crud and fuctionality 1 are ready

[cgeorgilakis]

Done as described

[cgeorgilakis]

Messages was updated( not deployed yet in cappacleis2)