The destroy callback in wlr_switch_impl has been removed. The function
`wlr_switch_finish` has been introduced to clean up the resources owned by a
wlr_switch.
`wlr_input_device_destroy` no longer destroys the wlr_switch, attempting to
destroy a wlr_switch will result in a no-op.
The field `name` has been added to the wlr_switch_impl to be able to identify
a given wlr_switch device.