Add keyboard support to Menubar

Migrated case from Manuscript.

Original case: https://pharo.fogbugz.com/f/cases/22091 Status: Work Needed Project: Usability Original Author: CyrilFerlicot Date: 8 June 2018 3:28:29 pm

Description:

What I would like:

Take focus when we press Alt
Left/right keys navigation
Top/bottom keys navigation
Been able to navigate the menus with the keyboard keys (For example press T for Tools and underline the T)

jecisc / Bazard