Make DMN editors focusable for keyboard binding

[jarekdanielak]

Is your feature request related to a problem? Please describe.

With the new implementation of focusable canvas and implicit keyboard binding in diagram-js@15, we should port this behavior over to DMN editors.

Currently DMN editors lack focus API and focusable elements which can be used for keyboard binding targets.

Describe the solution you'd like

Make DMN editors focusable to bind and unbind keyboard actions depending on the context in which user is working.

Describe alternatives you've considered

Leave it as it is.

New configuration style is already integrated with #921. We can decide not to work on any improvements.

Additional context

• This issue is a follow up to Port implicit keyboard binding over to decision editors #920
• Implementation in diagram-js Make canvas selectable / keyboard binding implicit diagram-js#662
• Tracking issue for integration across ecosystem: https://github.com/bpmn-io/internal-docs/issues/1081

[philippfromme]

@jarekdanielak Do we intend to work on this soon or should we move it to backlog for now?

[jarekdanielak]

I might pick it up as a follow up to implicit keyboard integration topic, but not in upcoming days. Moving to backlog.