lsp-extensions idea: Debuggables

So, rust-analyzer already supports runnables, which gives all the runnable targets in a neat list, so I was wondering if this could also be done for all the debuggable targets. This is more useful for editors like (neo)vim. I already have this implemented in rust-tools, which basically asks for runnables and then filters out the non debuggable commands out from it. This is not an ideal implementation, but in my experience it seems to work fine (haven't done any extensive testing though!).
Here's a small demo:

Start by reviewing rust-analyzer's existing runnable-target support and the linked rust-tools implementation that filters runnable commands into debuggable targets. Determine the intended LSP extension behavior and how debuggable targets should be represented for editors such as Neovim; done means an agreed design and corresponding editor-facing behavior.