Add workspace status item to the Language Status bar.

[JoeRobich]

This makes a little progress on #6675. It shows a work indicator for the initial workspace load. It will also show the open solution file name and provides a link for users to open a different solution. This does not move NuGet restore to the server nor does it show progress when reloading projects.

See related Roslyn PR: https://github.com/dotnet/roslyn/pull/74095

https://github.com/user-attachments/assets/314e4967-065a-4568-8b29-24004967a777