Test for #32086:

Complexity: 3

• Windows - @roblourens
• OS X - @jrieken
• Linux - @isidorn

In this milestone we've created a "real" API replacement for the 'startSession' and 'initialConfigurations' commands that we are currently using.
This API is proposed and can be found here.
To use the proposed API copy the vscode.proposed.d.ts it in your extension folder.

Verify that this API works as documented:

• use the "hello world" extension
• register a DebugConfigurationProvider for a specific debug type.
• implement provideDebugConfigurations by returning a real (or fake) launch configuration. Verify that this is added to the initial launch.json that is created if a project folder has none. Make sure that the correct workspaceFolder is passed to provideDebugConfigurations in the 0,1,n-folder workspace configurations.
• implement resolveDebugConfiguration by massaging the passed launch config and verify that it is passed to the correct debug adapter. Make sure that you can even change the type of the config so that another debug adapter is started. Make sure that the correct workspaceFolder is passed to resolveDebugConfiguration in the 0,1,n-folder workspace configurations.