feat: add saml request to link to sessions (#9001)

# Which Problems Are Solved

It is currently not possible to use SAML with the Session API.

# How the Problems Are Solved

Add SAML service, to get and resolve SAML requests.
Add SAML session and SAML request aggregate, which can be linked to the
Session to get back a SAMLResponse from the API directly.

# Additional Changes

Update of dependency zitadel/saml to provide all functionality for
handling of SAML requests and responses.

# Additional Context

Closes #6053

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

internal/static/i18n/en.yaml

@@ -550,6 +550,12 @@ Errors:
       Invalid: Token is invalid
       Expired: Token is expired
     InvalidClient: Token was not issued for this client
+  SAMLRequest:
+    AlreadyExists: SAMLRequest already exists
+    NotExisting: SAMLRequest does not exist
+    WrongLoginClient: SAMLRequest created by other login client
+  SAMLSession:
+    InvalidClient: SAMLResponse was not issued for this client
   Feature:
     NotExisting: Feature does not exist
     TypeNotSupported: Feature type is not supported
@@ -624,6 +630,8 @@ AggregateTypes:
   system: System
   session: Session
   web_key: Web Key
+  saml_request: SAML Request
+  saml_session: SAML Session
 
 EventTypes:
   execution: