Intellisense tooltip for local functions should show argument names

[Happypig375]

Is your feature request related to a problem? Please describe.
A function defined globally has its argument names shown in Intellisense tooltip, but not for functions in functions.

Describe the solution you'd like
Argument names should appear for functions in functions.

Describe alternatives you've considered
Nah

Additional context
Nope

[psfinaki]

Reopening to keep the track of the other case we still need to work on:

do
    let func x = ()
    ()

[vzarytovskii]

Reopening to keep the track of the other case we still need to work on:

do
    let func x = ()
    ()

If it fixes the case described in the original issue, we probably should close it and open a separate one for the one in 'do'. If not, let's leave it open.