* wip
* testing: implement related code
This implements a simple provider-based related code feature, and
adopts it in the selfhost test extension.
It's surfaced to users via automatic delegation in the "run tests at
cursor" command, which I feel like it very natural. I also add two
commands which reuse the `SymbolNavigationAction` to implement
go to/peek views using the references infrastructure. The upstream
change involved in this is the addition of the "go to" preference
for tests.
cc @jrieken @mjbvz
* bump distro for API enablement
