Dashboard: add FOLIO keyboard shortcuts

Stripes incorporates a set of keyboard shortcut keys for implementation across all apps. See:

• Section "Platform-wide keyboard shortcuts (each app must implement) " on the wiki page Key Navigation https://wiki.folio.org/display/A11Y/Keyboard+Navigation
• Keyboard commands API: https://github.com/folio-org/stripes-components/tree/master/lib/Commander

The following shortcuts should be implemented in Dashboard:

1. Create new widget (focus must be on any element on the Dashboard app) - option/alt + n 
2. Edit selected widget (focus must be on any element on the widget) - cmd/ctrl + option/alt + e >> de-scoped to ERM-1756
3. Save edit / new form changes (focus must be on any element on a form) - cmd/ctrl + s (applies to widget instance config screen)
4. Expand all accordions on detail record (focus must be on any element on the Edit pane) - cmd/ctrl + option/alt + b (applies to widget instance config screen)
5. Collapse all accordions on detail record (focus must be on any element on the Edit pane) - cmd / ctrl + option/alt + g (applies to widget instance config screen)
6. Open keyboard shortcuts modal cmd/ctrl + option/alt + k

Dev task breakdown

• Firstly implement existing patterns from ERM-1151, ERM-1239, ERM-1240, ERM-1241 
• Using this component, add a shortcut to open the modal.
• Existing shortcut code can be found by searching for HasCommand component
• No existing shortcut code in `defaultKeyboardShortcuts` for this, so append a new one for now  Check with Claudia who knows shortcuts code best atm