MM-20698: Add server support for getting SAML metadata and updating S… (#13311)

* MM-20698: Add server support for getting SAMl metadata and updating SAMl settings

tests/test-config.json

@@ -289,6 +289,7 @@
         "Encrypt": true,
         "IdpUrl": "",
         "IdpDescriptorUrl": "",
+        "IdpMetadataUrl": "",
         "AssertionConsumerServiceURL": "",
         "ScopingIDPProviderId": "",
         "ScopingIDPName": "",
@@ -401,4 +402,4 @@
         "CustomUrlSchemes": [],
         "ExperimentalTimezone": false
     }
-}
+}