feat: implement a PressKey action

packages/fluttium/lib/src/actions/press_key.dart

@@ -0,0 +1,61 @@
+import 'dart:ui';
+
+import 'package:flutter/services.dart';
+import 'package:fluttium/fluttium.dart';
+
+/// {@template press_key}
+/// TODO: docs
+/// {@endtemplate}
+class PressKey extends Action {
+  /// {@macro press_key}
+  const PressKey({
+    required this.key,
+    this.downFor = 1,
+  });
+
+  /// The key that is being pressed.
+  final String key;
+
+  /// For how long the key will be down.
+  final int downFor;
+
+  @override
+  Future<bool> execute(Tester tester) async {
+    final logicalKey = LogicalKeyboardKey.knownLogicalKeys.firstWhere((key) {
+      return key.debugName == this.key;
+    });
+
+    final physicalKey = PhysicalKeyboardKey.knownPhysicalKeys.firstWhere((key) {
+      return logicalKey.debugName == key.debugName;
+    });
+
+    tester.keyEventManager.handleKeyData(
+      KeyData(
+        type: KeyEventType.down,
+        physical: physicalKey.usbHidUsage,
+        logical: logicalKey.keyId,
+        timeStamp: Duration.zero,
+        character: null,
+        synthesized: false,
+      ),
+    );
+
+    await tester.pump(duration: Duration(milliseconds: downFor));
+
+    tester.keyEventManager.handleKeyData(
+      KeyData(
+        type: KeyEventType.up,
+        physical: physicalKey.usbHidUsage,
+        logical: logicalKey.keyId,
+        timeStamp: Duration.zero,
+        character: null,
+        synthesized: false,
+      ),
+    );
+
+    return true;
+  }
+
+  @override
+  String description() => 'Press key: $key';
+}