Labels should not get type 'any' for their quick info

[DanielRosenwasser]

We falsely report a label having type any.

[GuillaumeSalles]

I tried to fix it in pr #2731

[CyrusNajmabadi]

Notes:

1. Labels should have symbols just like anything else. (This also matches Roslyn).
2. Labels should get quick info. They should just get meaningful quick info. Things like goto-def, find-references should work on them (ideally without any specialized code. it should just fall out from them being normal symbols.

[DanielRosenwasser]

What kind of meaningful quick-info did you have in mind?

I'd think perhaps a preview of the statement it's relevant to, but that's arguable. In any case, I think until we discuss and nail that down, we shouldn't show anything for the time being.

[CyrusNajmabadi]

A preview of the statement its relevant to. C# has something similar when you hover over a closing brace. it's quite useful.

[mhegazy]

Fixed in #2731. Thanks @GuillaumeSalles