Implement additionalGroups functionality (#2)

queries/src/snapshots/queries__tests__create_user_gql_output.snap

@@ -7,6 +7,7 @@ mutation CreateUser($username: String!) {
     id
     groups {
       id
+      displayName
     }
   }
 }

queries/src/snapshots/queries__tests__get_groups_gql_output.snap

@@ -0,0 +1,10 @@
+---
+source: queries/src/lib.rs
+expression: operation.query
+---
+query GetGroups {
+  groups {
+    id
+    displayName
+  }
+}

queries/src/snapshots/queries__tests__get_user_gql_output.snap

@@ -7,6 +7,7 @@ query GetUser($username: String!) {
     id
     groups {
       id
+      displayName
     }
   }
 }

queries/src/snapshots/queries__tests__remove_user_from_group_gql_output.snap

@@ -0,0 +1,9 @@
+---
+source: queries/src/lib.rs
+expression: operation.query
+---
+mutation RemoveUserFromGroup($group: Int!, $username: String!) {
+  removeUserFromGroup(groupId: $group, userId: $username) {
+    ok
+  }
+}