feat: add remove "displayname" field

crates/quark/src/impl/generic/users/user.rs

@@ -68,6 +68,7 @@ impl User {
                     x.background = None;
                 }
             }
+            FieldsUser::DisplayName => self.display_name = None,
         }
     }
 

crates/quark/src/impl/mongo/users/user.rs

@@ -337,6 +337,7 @@ impl IntoDocumentPath for FieldsUser {
             FieldsUser::ProfileContent => "profile.content",
             FieldsUser::StatusPresence => "status.presence",
             FieldsUser::StatusText => "status.text",
+            FieldsUser::DisplayName => "display_name",
         })
     }
 }