It's allowed to assign multiple actions to the same keyboard shortcut. Actions system filters them on the current
context basis during processing (e.g., we can have two actions assigned to the same shortcut, but one of them is
configured to be inapplicable in modal dialog context).
However, there is a possible case that there is still more than one action applicable for particular keyboard shortcut
after filtering. The first one is executed then. Hence, actions processing order becomes very important.
Current key allows specifying custom actions sorter to use if any. I.e., every component can define its custom
sorting rule to define priorities for target actions (classes of actions).