[Feature Request]: add variable collapse keymap

[ZSaberLv0]

Is your feature request related to a problem? Please describe.
there's mappings.variables.expand_collapse, but no way to collapse, which is a pain when inspecting deeply chained objects

Describe the solution you'd like
add two keymap:

• mappings.variables.collapse : collapse to parent level
• mappings.variables.collapse_all : collapse all variable, until reach root level

[puremourning]

Hmm. I thought I had mapped za like the fold commands for this. Maybe only in my local.

I’ll check. I agree we can add something here.