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.

enable-ohos.ps1

@@ -0,0 +1,46 @@
+# Enables the OpenHarmony Flutter toolchain for the current PowerShell session.
+# This script does not change the system or user PATH permanently.
+
+$ErrorActionPreference = 'Stop'
+
+$flutterBin = 'C:\Users\A200477427\Developments\flutter_flutter\bin'
+$devecoHome = 'C:\Program Files\Huawei\DevEco Studio'
+$devecoSdk = "$devecoHome\sdk"
+$ohpmBin = "$devecoHome\tools\ohpm\bin"
+$hvigorBin = "$devecoHome\tools\hvigor\bin"
+
+$requiredDirectories = @($flutterBin, $devecoSdk, $ohpmBin, $hvigorBin)
+$missingDirectories = $requiredDirectories | Where-Object {
+  -not (Test-Path -LiteralPath $_ -PathType Container)
+}
+
+if ($missingDirectories) {
+  throw "OpenHarmony tool directories were not found:`n$($missingDirectories -join "`n")"
+}
+
+# Set these only for this terminal. This also makes the script work in a terminal
+# that was opened before the corresponding Windows environment variables existed.
+$env:DEVECO_HOME = $devecoHome
+$env:DEVECO_SDK_HOME = $devecoSdk
+
+# Put the OpenHarmony-specific commands first for this terminal only. Remove
+# duplicate entries so repeated execution of this script leaves PATH clean.
+$pathDirectories = @($flutterBin, $ohpmBin, $hvigorBin)
+$pathEntries = $env:Path -split ';' | Where-Object {
+  $_ -and $_ -notin $pathDirectories
+}
+$env:Path = ($pathDirectories + $pathEntries) -join ';'
+
+$commands = @('flutter', 'ohpm', 'hvigorw')
+$unavailableCommands = foreach ($command in $commands) {
+  if (-not (Get-Command $command -ErrorAction SilentlyContinue)) {
+    $command
+  }
+}
+
+if ($unavailableCommands) {
+  throw "The following commands could not be resolved from PATH: $($unavailableCommands -join ', ')"
+}
+
+Write-Host 'OpenHarmony Flutter environment is enabled for this PowerShell session.' -ForegroundColor Green
+Get-Command $commands | Select-Object Name, Source, CommandType | Format-Table -AutoSize