Implemented using a custom invoke method which doesn't call the callback, and
instead calls parent disable passing the callback as argument.
This fix ensures that if a modem gets removed, no invalid modem reference is
passed to the parent disable, as info->modem would be set to NULL and we can
detect it in the custom invoke method.
Pass the device's hardware IDs through modem creation and use them
when calculating the device's identifier. Add a bunch of testcases
for real hardware to ensure we don't break the device ID in the
future unless we really want to.
