Run persistent mode tests in CI (#15029)

* Add command to run tests in persistent mode

* Convert Suspense fuzz tester to use noop renderer

So we can run it in persistent mode, too.

* Don't mutate stateNode in appendAllChildren

We can't mutate the stateNode in appendAllChildren because the children
could be current.

This is a bit weird because now the child that we append is different
from the one on the fiber stateNode. I think this makes conceptual
sense, but I suspect this likely breaks an assumption in Fabric.

With this approach, we no longer need to clone to unhide the children,
so I removed those host config methods.

Fixes bug surfaced by fuzz tester. (The test case that failed was the
one that's already hard coded.)

* In persistent mode, disable test that reads a ref

Refs behave differently in persistent mode. I added a TODO to write
a persistent mode version of this test.

* Run persistent mode tests in CI

* test-persistent should skip files without noop

If a file doesn't reference react-noop-renderer, we shouldn't bother
running it in persistent mode, since the results will be identical to
the normal test run.

* Remove module constructor from placeholder tests

We don't need this now that we have the ability to run any test file in
either mutation or persistent mode.

* Revert "test-persistent should skip files without noop"

Seb objected to adding shelljs as a dep and I'm too lazy to worry about
Windows support so whatever I'll just revert this.

* Delete duplicate file