Execute more specific test names for minitest specs

[Earlopain]

Motivation

This will close #1605, do most of what is actually possible for #1604 and adress #1606 (comment)

Implementation

Use the group stack for spec as well. This removes most of the distinction these two previously had.

minitest_spec_halfwritten simulates a user typing new specs. It mostly tests that the group ids being sent to vscode are well formed so something like in #1605 doesn't happen. It shows codelenses for everything which isn't entirely correct, but I think that's better than it shifting around during typing.

I changed the reference marker into something that won't be escaped by shellescape. It needs to happen at the end, and when modified that doesn't work out.

Spec test names will look like this: test_.*_my_test, where .* is the 0001 part. Having the actual numbers there would require keeping track of how many its a describe block has encountered and might also just not be possible if there's something that defines tests outside of it because the numbers would then always be off.

Automated Tests

Added something for the variations I could come up with.

Manual Tests

Tested code lenses for the modified/added expections execute the correct tests.