Keyboard shortcuts for Uses in Code Browser
Fix for bug/wish 245902. Use the IToolActionViewer to implement
this feature: When the code browser is open and shows uses you can
now navigate through all uses by pressing F4 and Shift+F4. The Use
that is selected will also be opened, just like clicking on it.
Test Plan: Manual Testing
Reviewed By: mwolff
Differential Revision: https://phabricator.kde.org/D4483