[Testing] Allow test runs to run tests outside of the original scope

[pavelfeldman]

Does this issue occur when all extensions are disabled?: No

• VS Code Version: 1.90
• OS Version: all

Context
We have a notion of project/test dependencies, so when I run a test TEST, I might need to run another SETUP test first. This however is not supported out of the box - if my SETUP test is outside of the scope of TEST, no rendering on its progress happens in the sidebar.

Workaround
The way I work around it is I create a new test run with a root of the workspace in it. Then it reports progress on all the tests.

Side-effect
It has a following side effect though: one "Test run" history entry is created for the original handle invocation and another one is created for my createTestRun

Request
I'd say there are two requests here:

1. Only create test log entry when createTestRun is invoked, do not create one automatically.
2. Allow for tests outside of the original scope to show their progress

//cc @connor4312

[connor4312]

Yea, we can probably remove the restriction. I put it there when I first made the API to be a guardrail against invalid logic from extensions, but if there's a use case for it I'm fine removing it.