Make Stride.Launcher crossplatform

[Jklawreszuk]

Is your feature request related to a problem? Please describe.
As a developer I want to run Stride Launcher on any desktop platform. This will be first step to make GameStudio cross-platform.

Describe the solution you'd like
First idea is just to port it to AvaloniaUI. Many lines of code can be easy translated and I've already made proof of concept project, but It needs some help.

• Is the feature affecting behaviour in the editor?
  In theory, it should not.

[ykafia]

Another idea could be building it as a dotnet tool, this way it'd be installed pretty easily by just having dotnet cli, and the cli will handle the update notifications

[Jklawreszuk]

This sounds good, but I think there should also be a graphical way to manage game projects, especially for beginners.

[ykafia]

A dotnet tool can be a gui app that you can launch from the console :-)
Monogame's asset manager is a gui tool that's been made as a dotnet tool too

[Jklawreszuk]

Oh, I forgot about that😅. If so, I'll try to figure out how to wrap it as a dotnet tool. Also, Stride.Launcher is already distributed as a nuget package, so this package could be replaced by a dotnet tool in the future, right?

[Jklawreszuk]

@Kryptos-FR implementation on xplat-editor branch seems to be complete and I'm willing to try cherrypicking changes on the master.

[Kryptos-FR]

@Jklawreszuk I'll have a look at it tomorrow. I can update to the latest Avalonia and make sure everything still works. There is small hack to make the crash report work and that could break in future Avalonia versions.

[Kryptos-FR]

@Jklawreszuk #2970 should be merged first as it's going to create additional conflicts. In the meantime I'm merging current master into the xplat-editor branch to solve the existing conflicts.

edit: I have cherry-picked the Launcher from the xplat-editor branch in a new branch named feature/launcher-avalonia-cherrypick, and a draft PR #3027.