Return editable URL navigator to breadcrumb mode if it has focus and...

Return editable URL navigator to breadcrumb mode if it has focus and everything is selected and when Ctrl+L is pressed

Summary:
This patch makes an editable location bar return to breadcrumb mode when {key Ctrl L} is pressed, but only if the location bar currently has focus and everything is selected. Otherwise, it will simply return focus to it as before.

This provides a slightly easier way to make the location bar return to breadcrumbs mode

Test Plan:
- Compile and deploy and make the location bar be breadcrumbs
- Hit {key Ctrl L} twice in a row -> location field turns to being in breadcrumb mode. Focus is correctly returned to the main view.
- Hit {key Ctrl L}, move focus elsewhere, then hit {key Ctrl L} again -> Location bar is editable and focused with everything selected.
- Hit {key Ctrl L}, deselect some of the text, then hit {key Ctrl L} again -> Location bar selects everything.

Reviewers: #dolphin, elvisangelaccio, dhaumann

Reviewed By: elvisangelaccio, dhaumann

Subscribers: elvisangelaccio, dhaumann, kfm-devel

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D16980