feat!: Adds new route methods pushReplacement, pushReplacementNamed, and pushReplacementOverlay

packages/flame/lib/src/components/route.dart

@@ -45,10 +45,10 @@ class Route extends PositionComponent with ParentIsA<RouterComponent> {
  final bool maintainState;
 
  /// The name of the route (set by the [RouterComponent]).
- String get name => _name;
- late String _name;
+ String? get name => _name;
+ late String? _name;
  @internal
- set name(String value) => _name = value;
+ set name(String? value) => _name = value;
 
  /// The function that will be invoked in order to build the page component
  /// when this route first becomes active. This function may also be `null`,

packages/flame/lib/src/components/router_component.dart

@@ -256,11 +256,6 @@ class RouterComponent extends Component {
 
  /// Local method to bypass [pop]'s assert
  void _popWithoutMinimumAssert() {
- assert(
- _routeStack.isNotEmpty,
- 'There must be a route to pop.',
- );
-
  final route = _routeStack.removeLast();
  route.didPop(_routeStack.last);
  route.removeFromParent();