Adding IdAttribute setting for SAML (#9291)

* Adding IdAttribute setting for SAML

* Adding Saml Id Attribute to the diagnostics information

* Adding entry to default.json

config/default.json

@@ -318,6 +318,7 @@
         "IdpCertificateFile": "",
         "PublicCertificateFile": "",
         "PrivateKeyFile": "",
+        "IdAttribute": "",
         "FirstNameAttribute": "",
         "LastNameAttribute": "",
         "EmailAttribute": "",