Add support for touch events in fakeinput protocol and interface.

Summary:
This adds support for following in fakeinput interface:

- touch_down
- touch_motion
- touch_up
- touch_cancel
- touch_frame

Test Plan: added autotests passes

Reviewers: #plasma, bshah, graesslin

Reviewed By: #plasma, bshah, graesslin

Subscribers: bshah, graesslin, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D1672