refactor empty state logic in CreateGroupView

The diff introduces boolean variables `doneLoading` and `snapshotDataEmpty` to simplify the conditional check for displaying the empty state message. It specifically fixes the logic to correctly show the "No players found" message when both the snapshot and the local `allPlayers` list are empty, removing the dependency on `selectedPlayers.isEmpty`.

lib/presentation/views/main_menu/create_group_view.dart

@@ -209,12 +209,13 @@ class _CreateGroupViewState extends State<CreateGroupView> {
                                 ),
                               );
                             }
-                            if (snapshot.connectionState ==
+                            bool doneLoading =
-                                    ConnectionState.done &&
+                                snapshot.connectionState ==
-                                (!snapshot.hasData ||
+                                ConnectionState.done;
-                                    snapshot.data!.isEmpty ||
+                            bool snapshotDataEmpty =
-                                    (selectedPlayers.isEmpty &&
+                                !snapshot.hasData || snapshot.data!.isEmpty;
-                                        allPlayers.isEmpty))) {
+                            if (doneLoading &&
+                                (snapshotDataEmpty && allPlayers.isEmpty)) {
                               return const Center(
                                 child: TopCenteredMessage(
                                   icon: Icons.info,