synapse: Support configuring login via oidc provider

roles/synapse/meta/argument_specs.yaml

@@ -88,6 +88,29 @@ argument_specs:
         default: []
         elements: str
 
+      synapse_oidc_provider_client_id:
+        type: str
+        required: false
+        default: ""
+      synapse_oidc_provider_name:
+        description: Required if synapse_oidc_provider_client_id is set
+        type: str
+      synapse_oidc_provider_client_secret:
+        description: Required if synapse_oidc_provider_client_id is set
+        type: str
+      synapse_oidc_provider_issuer:
+        description: Required if synapse_oidc_provider_client_id is set
+        type: str
+      synapse_oidc_provider_scope:
+        description: Required if synapse_oidc_provider_client_id is set
+        type: list
+        elements: str
+      synapse_oidc_provider_mas_claims_imports:
+        description:
+          - Passed to matrix authentication service.
+          - See https://element-hq.github.io/matrix-authentication-service/setup/sso.html#user-attributes-mapping
+        type: dict
+
       synapse_postgres_tag:
         description: Postgres tag to use for synapse postgres container
         type: str