feat: Add build info and localization for entry app

- Introduced buildinfo.json5 to enable impeller feature.
- Added Chinese localization strings in string.json for module description and entry ability.
- Created Ability.test.ets for unit testing of ability functionalities.
- Implemented List.test.ets to run the ability tests.
- Developed TestAbility.ets to manage test execution and lifecycle events.
- Created Index.ets as a testability page with UI components.
- Added OpenHarmonyTestRunner.ts for managing test execution in OpenHarmony.
- Defined module.json5 for entry_test module configuration.
- Established color.json and string.json for base resources.
- Included icon.png for the test module.
- Created test_pages.json to define testability page sources.
- Configured hvigor and oh-package.json5 for project setup.
- Updated pubspec.yaml and related files to downgrade Dart SDK to 3.11.0 and adjust dependencies.
- Added PowerShell script to enable OpenHarmony Flutter toolchain.
- Updated multiple package pubspec.yaml files to align with Dart SDK version 3.11.0 and adjust dependencies accordingly.

app/ohos/AppScope/app.json5

@@ -0,0 +1,10 @@
+{
+  "app": {
+    "bundleName": "com.conti.app",
+    "vendor": "example",
+    "versionCode": 1000000,
+    "versionName": "1.0.0",
+    "icon": "$media:app_icon",
+    "label": "$string:app_name"
+  }
+}

app/ohos/AppScope/resources/base/element/string.json

@@ -0,0 +1,8 @@
+{
+  "string": [
+    {
+      "name": "app_name",
+      "value": "app"
+    }
+  ]
+}