This will allow to move code/data to the specific console types.

Replace console_type_t with object type check.

QemuConsole can be abstract.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230830093843.3531473-21-marcandre.lureau@redhat.com>