refactor: reduce timeline rebuilds (#19704)

* reduce timeline rebuilds

* feat: adds bottom sheet map and actions (#19692)

* adds bottom sheet map and actions

* PR feedbacks

* only reload the asset viewer if asset is changed

* styling tweak

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>
Co-authored-by: Alex <alex.tran1502@gmail.com>

* rename singleton and remove event prefix

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>
Co-authored-by: Alex <alex.tran1502@gmail.com>

mobile/lib/domain/utils/event_stream.dart

@@ -0,0 +1,48 @@
+import 'dart:async';
+
+sealed class Event {
+  const Event();
+}
+
+class TimelineReloadEvent extends Event {
+  const TimelineReloadEvent();
+}
+
+class EventStream {
+  EventStream._();
+
+  static final EventStream shared = EventStream._();
+
+  final StreamController<Event> _controller =
+      StreamController<Event>.broadcast();
+
+  void emit(Event event) {
+    _controller.add(event);
+  }
+
+  Stream<T> where<T extends Event>() {
+    if (T == Event) {
+      return _controller.stream as Stream<T>;
+    }
+    return _controller.stream.where((event) => event is T).cast<T>();
+  }
+
+  StreamSubscription<T> listen<T extends Event>(
+    void Function(T event)? onData, {
+    Function? onError,
+    void Function()? onDone,
+    bool? cancelOnError,
+  }) {
+    return where<T>().listen(
+      onData,
+      onError: onError,
+      onDone: onDone,
+      cancelOnError: cancelOnError,
+    );
+  }
+
+  /// Closes the stream controller
+  void dispose() {
+    _controller.close();
+  }
+}