LSP: Inline/inlay hints

[fahim2690]

Lisette 0.4.0 adding goto for stdlib typedefs has improved the DX significantly (for me, at least), but I'm still too used to seeing inline hints (function/method parameter names, variable types, etc) in my IDE. I hope this functionality can be introduced to the Lisette LSP.

[ivov]

Addressed with lisette-v0.4.2

[fahim2690]

Thanks a lot for the quick addition, there are some minor nits but otherwise it works.

Nits:

• the inline hint is sometimes displayed in the wrong location (seems to be happening for pointer derefs and slice indices specifically).

• variadic params don't seem to be getting hinted.

[ivov]

Solved by @stormpat at #742 in the upcoming lisette-v0.4.3