Ever since the effects were changed to static, each test of the
integration tests includes all the effects. The result of this is that
when doing a debug build each test is now 60MiB or more. With the amount
of tests, this results in ~8 GiB of diskspace used just for KWin's
binary output directory, which is rather excessive.
Since the tests all share a common framework library, we can change that
library to a shared library and that way avoid linking all the effects
into each test.
Most of this is shuffling around some link libraries in the integration
test CMakeLists, however, I needed to export the Xwayland class as it is
used by one of the tests but wasn't exported.