Connected gamepads are stored on the Navigator, which means that when we
navigate to a new test, they stick around, including the virtual ones
we create for testing purposes. This caused issues such as the one
fixed in #7329 where failing to manually disconnect a virtual gamepad
meant that it would interfere with subsequent tests.
We don't want to rely on tests cleaning things up correctly, so this
commit introduces an automatic clean-up of these virtual gamepads.
InternalGamepad objects are now tracked in Internals, and all
disconnected in `Internals::perform_per_test_cleanup()`. It's named
generically as I'm expecting other systems (eg, localStorage or
cookies) to want similar cleanup between tests, but implementing those
is left as an exercise for a future person.
This method is called from signal_test_is_done(). This method is always
called in the case where the test completes. A test that crashes means
the WebContent isn't reused. A test that times out should also not have
its WebContent process reused, though it's not clear to me what we
currently do there.
Verified by commenting-out the `gamepad.disconnect()` line from the
Text/input/GamepadAPI/gamepad-is-available-in-new-navigables.html test
and then running:
```bash
for run in {1..20}; do
Meta/ladybird.py run test-web -s -j1 -f GamepadAPI;
done
```
We have to prevent from including any SDL headers in LibWeb headers.
Otherwise there will be transitive Windows.h includes that will
re-declare some of our existing forward decls/defines in
LibCore/SocketAddressWindows.h
