Re-add Url editor and add KPropertyGenericSelectionEditor

Authored by staniek.

Description

Re-add Url editor and add KPropertyGenericSelectionEditor

Summary: + update the example app

Test Plan: Try the kpropertyexample: Url, Existing File, Overwrite File, Dir properties.

Reviewers: piggz

Subscribers: Kexi-Devel-list

Differential Revision: https://phabricator.kde.org/D806

Details