Created 'remote' section

Summary:
Group all network related urls into the 'remote' section, to make it
clear to the user what is access through network or not

Depends on D8332
Depends on D8348

Test Plan:
From any kde app try to open/save a file.
It should show a new file dialog with network urls under 'remote' section

Reviewers: ngraham, Frameworks, Dolphin, mwolff, mlaurent, dfaure

Reviewed By: ngraham, Dolphin, mwolff, mlaurent, dfaure

Subscribers: dfaure, elvisangelaccio, mwolff, mlaurent, Frameworks

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D8434