Support for artifacts output layout

[salty-flower]

First of all, thank you for making Blazor browser extensions possible!

Current Behavior

Currently, it doesn't fully support Artifacts output layout, which enables a centralized build output folder.

CSC : warning CS8785: Generator 'BackgroundSourceGenerator' failed to generate source. It will not contribute to the output and compilation errors may occur as a result. Exception was of type 'DirectoryNotFoundException' with message 'Could not find a part of the path '$(ProjectDir)\obj\BackgroundWorkerMain.generated.js'.'. [$(ProjectDir)$(ProjectName).csproj]
~\.nuget\packages\blazor.browserextension\2.0.0\build\Blazor.BrowserExtension.Config.targets(50,5): error : An unexpected error occurred when writing option file '$(ProjectDir)$(ArtifactsPath)\obj$(ProjectName)\debug\browserextension\build\browserextension.config.json' [$(ProjectDir)$(ProjectName).csproj]
~\.nuget\packages\blazor.browserextension\2.0.0\build\Blazor.BrowserExtension.Config.targets(50,5): error : The filename, directory name, or volume label syntax is incorrect. : '$(ProjectDir)$(ArtifactsPath)\obj$(ProjectName)\debug\browserextension\build' [$(ProjectDir)$(ProjectName).csproj]

Expected Behavior

The build should succeed and write to the centralized folder.

Potential Solution

Consider change the current$(ProjectDir)$(IntermediateOutputPath) in Blazor.BrowserExtension.Config.targets to a more flexible path structure.