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

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