User Story::
As a user having problems with mouse use, I want to open revision slider.
Context of use:
I assume the user would use the keyboard, if not via accesskeys via TABbing
Current Problems:
When the header bar of the slider accordion widget is focused using tabbing, it still can’t be opened by the standard-toggle via space or enter key
Possible Solution:
On pressing Space or Enter while focusing the header bar the revision slider should open. After opening it once via mouse, the open/closing via keyboard works! So the event trigger for this probably needs to be added to the lazy load JS.