Move test middleware out of CoreServiceProvider

Seems pretty straight forward move.

Per 🐛 [random test failure] PathAliasTest::testPathCache Active let's try to move the wait terminate stuff into a test module that is then enabled only by the tests that need it.

Better yet, let's use a container param instead of using state or keyvalue.

If we wanted to take this further we could introduce a new function like ::setContainerParameter that adds a service to the yaml instead. Then we wouldn't need the parameter at all and could just add the service when it's needed. That would tidy up FunctionalTestSetupTrait::prepareSettings a bit too.

I wasn't sure if rebuilding the container would make the tests slower, but the tests I ran were almost identical compared to HEAD. Performance tests seem to pass too, and I think enabling a module with its own service provider would require the container to be rebuilt anyway.

Updated the IS to match the current solution, this is ready for review.

Oh that is so much nicer!

Nice approach!

Rebased locally as there was a conflict in WaitTerminateTestTrait

This is a huge improvement, great job @mstrelan

Committed/pushed to 11.x, thanks!

catch → closed merge request !11529

Automatically closed - issue fixed for 2 weeks with no activity.