Inlay hints: Allow ctrl/cmd+click to go to a type's definition

[Tyriar]

Testing #129381

I tried ctrl+clicking TerminalIcon here intuitively:

Going to an argument definition would also be handy/expected

[Tyriar]

In a similar vein, the hover for the inlays should show for the type they're hovering imo

[hediet]

I don't know what the plans are for inlay hints, but I think this is doable with injected text.
However, the injected text feature needs to be extended to support hovers & decorations that just apply to a specific part of the injected text.

[mjbvz]

@jrieken Adding you since I believe VS Code's inlay hints api would need to be modified to support this

[jrieken]

Yeah, we want that