The name of The Compositor Modules should be capitalized.

It is more an example of how to use The Compositor Modules, not a test.

As an exmaple it is sufficient to run it from the build directory.

This was only in the .gitlab-ci.yml file.

We have ported most of the pipeline to GitHub Actions. Since it's unused here
on GitHub anyway let's remove it.

The manual tests go into a separate subdirectory.

The function is not used and we can remove the last test still using Qt Test.

Unit tests are now in a separate unit directory.

It's the standard naming scheme in most projects and it cleans up the toplevel
directory some more.

They are not in use at the moment and outdated.

This is really relevant only for the KDE Plasma desktop. It's therefore a
better suited place.

This might need to be revisited though when we have a more generic
configuration API.

Most files already respected the style.

Minico doesn't use scripting and input is already included by the base platform
header.

This is then using the same pattern like for the other platform objects.