Add QemuInputEvent as the input subsystem's name for InputEvent and use
it in input handler, queue, and replay interfaces.
This prepares for decoupling QEMU's internal input event representation
from the QAPI InputEvent type.
Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20260520-input-v3-1-7c9e4c7abe34@rsg.ci.i.u-tokyo.ac.jp>
a0f5963a30