Add KCM for controlling KWin's Night Color module

Simple but powerful KCM utilizing LibColorCorrect from Plasma Workspace
to provide configuration of Night Color in KWin.

Reviewers: #plasma, davidedmundson

Reviewed By: #plasma, davidedmundson

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D5932