Add ability to copy links for rooms and spaces

lib/widgets/chat_page/room_menu.dart

@@ -0,0 +1,33 @@
+import "package:clipboard/clipboard.dart";
+import "package:flutter/material.dart";
+import "package:matrix/matrix.dart";
+
+class RoomMenu extends StatelessWidget {
+  final Room room;
+  const RoomMenu(this.room, {super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final danger = Theme.of(context).colorScheme.error;
+
+    return PopupMenuButton(
+      itemBuilder: (_) => [
+        PopupMenuItem(
+          onTap: () async {
+            final link = await room.matrixToInviteLink();
+            await FlutterClipboard.copy(link.toString());
+          },
+          child: ListTile(leading: Icon(Icons.link), title: Text("Copy Link")),
+        ),
+        PopupMenuItem(
+          onTap: () =>
+              showDialog(context: context, builder: (context) => AlertDialog()),
+          child: ListTile(
+            leading: Icon(Icons.logout, color: danger),
+            title: Text("Leave", style: TextStyle(color: danger)),
+          ),
+        ),
+      ],
+    );
+  }
+}