[kcmkwin] Add a new config module for touch screen gestures

Summary:
This is basically a copy of the screen edges config module with
everything removed which does not matter. This is lazy and could
be done with more code sharing. But it would be better to redesign
both kcms in a modern way instead of investing lots of time on
sharing code.

Test Plan:
Installed, opened it and verified it had the config selected
I had manually set.

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D5282