Workspaceslib ut (#40007)

This pull request introduces a new unit testing framework for the
`WorkspacesLib` module, adds test coverage for various utilities, and
integrates the new test project into the build system. Key changes
include adding the `WorkspacesLibUnitTests` project, implementing tests
for `AppUtils`, `JsonUtils`, and `PwaHelper`, and updating the build
configuration to include the new test project.

### Unit Tests Added:
* **`AppUtilsTests`**:
- Added comprehensive tests for methods such as `GetCurrentFolder`,
`IsEdge`, `IsChrome`, and `IsSteamGame` to validate their behavior under
various conditions.
* **`JsonUtilsTests`**:
- Implemented tests for reading and writing workspace data, including
scenarios for invalid JSON, non-existent files, and valid workspace
lists.
* **`PwaHelperTests`**:
- Added tests to ensure the stability of `PwaHelper` methods, such as
`GetEdgeAppId`, `GetChromeAppId`, and `SearchPwaName`, even with invalid
or empty inputs.

### Build System Updates:
* **New Test Project Integration**:
- Added the `WorkspacesLibUnitTests` project to the solution file
`PowerToys.sln` with appropriate dependencies.
- Updated build configurations to include the new test project for both
Debug and Release builds across architectures.
[[1]](diffhunk://#diff-ca837ce490070b91656ffffe31cbad8865ba9174e0f020231f77baf35ff3f811R2208-R2215)
[[2]](diffhunk://#diff-ca837ce490070b91656ffffe31cbad8865ba9174e0f020231f77baf35ff3f811R2841)

### Pipeline Adjustments:
* **Test Discovery**:
- Updated the pipeline configuration in
`.pipelines/v2/templates/job-build-project.yml` to discover the new
`WorkspacesLibUnitTests.dll` during test runs.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

.pipelines/v2/templates/job-build-project.yml

@@ -397,6 +397,7 @@ jobs:
           **\UnitTests-CommonLib.dll
           **\PowerRenameUnitTests.dll
           **\UnitTests-FancyZones.dll
+          **\\WorkspacesLibUnitTests.dll
           !**\obj\**
 
   - pwsh: |-