Notebook add shortkey to collapse all cells and clear all results

[Ossy81]

Is your feature request related to a problem? Please describe.
Add more shortkeys for notebooks like easy way to collapse/expand ALL cells. Clear all results with 1 key etc.

Describe the solution or feature you'd like
Add shortkeys to make it easier to use notebooks

Describe alternatives you've considered
No alternative. Doing everything 1 by 1

Additional context
Add any other context or screenshots about the feature request here.