Add external servers preference to graphql

Co-authored-by: Elias Schriefer

noise.graphql

@@ -27,11 +27,10 @@ type User {
 # All account preferences for a single user
 type UserPreferences {
     privacyPreference: PrivacyPreference!
-    # TODO: notifications
     notificationPreference: NotificationPreference!
-    # TODO: external servers
-    # TODO: security
     securityPreference: SecurityPreference!
+    # TODO: external servers
+    externalServersPreference: ExternalServersPreference!
 }
 
 type PrivacyPreference {
@@ -67,6 +66,12 @@ type SecurityPreference {
     passwordHash: String!
 }
 
+type ExternalServersPreference {
+    privacyPreference: PrivacyPreference
+    externalServers: RestrictionPolicy!
+    externalServersLimit: [Url!]
+}
+
 # Everyone = Including all = Excluding none
 # None = Including none = Excluding all
 enum RestrictionPolicy {