Keep things sorted alphabetically in CMakeLists.txt

Summary:
Currently component names and filenames are partially sorted. This makes adding
new items and finding existing items more difficult.

Test Plan: Compiles.

Reviewers: #kwin, gladhorn

Reviewed By: #kwin, gladhorn

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D24018