[SUGGESTION] Loading specific sln files from command line or environment variables

Describe the feature you'd like

Our team (CloudBuild) has a very large C# codebase that Visual Studio struggles to load. We use Microsoft.Build.Traversal instead of a single solution, and generate our solutions with slngen.

Therefore, there's no .sln file until slngen has been called. Instead, we have a bunch of .csproj. To make things worse, we develop build engines and therefore have a bunch of .sln files that are actually adhoc data for tests sprawled all over our repository.

In this use-case, the C# Dev Kit doesn't really work well because it will typically open any random test .sln file which will often fail to restore (because it's a test!).

Ideally, one would be able to specify the .sln file to open via command line or environment variables.

Alternatives considered

The only workaround I know is to manually open the sln file in the Solution Explorer. However, because we have a very large repository one typically switches sln files relatively often, so this quickly turns bothersome.

Environment Information

• OS: Windows
• VS Code: 1.83
• Extension Version: 0.5.150

The issue does not name files or tests; start by tracing how the extension discovers and opens solution files. Check the existing command-line and environment-variable handling, then define completion as allowing an explicit .sln path to be selected instead of opening an arbitrary repository solution.