Add coin:azure_domain_hint metadata property to manage

Author: baszoetekouw

roles/manage/templates/metadata_configuration/saml20_idp.schema.json.j2

@@ -370,6 +370,11 @@
         "coin:policy_enforcement_decision_required": {
           "type": "boolean",
           "info": "Set to activate the user policy engine (PDP) for this IdP."
+        },
+        "coin:azure_domain_hint": {
+          "type": "string",
+          "default": "",
+          "info": "the domain set here is sent to the IdP; Microsoft EntraID uses it to skip the account picker."
         }
       },
       "patternProperties": {