This ensures we get progress events when replugging a device. Also, remove the
callbacks on the 'old' device to avoid causing multiple events on a 2nd-replug.
When changing from runtime->bootloader->runtime the usual way of handling this
in a fwupd plugin is to:
* reset the device and wait for a replug
* flash the hardware
* reset the device and wait for a replug
This works well when the runtime and bootloader modes are handled by the same
plugin. For situations like the Nitrokey device, where one plugin handles the
runtime (nitrokey), and another handles the bootloader (dfu) we have to have
the ability to 'ignore' the device removal and just issue a 'changed' signal
so the client refreshes the properties.
In the case where we can trigger the replug automatically we can have to wait
for a USB re-enumeration (typically a few hundred ms) but when the user is
requred to unplug, and then replug we have to wait a bit longer.
The 'remove delay' allows us to modify per-device the removal delay. In the
case the device does not show back up in the correct time the device will be
auto-removed and the session will get a DeviceRemoved signal. In the case where
the device in bootloader mode shows up within the timeout the session just gets
a DeviceChanged event.
For the duration of the delayed removal the flags for the device are set to
zero to ensure the session does not try to interact with the device whilst
re-enumerating.
This moves more functionality out of the engine, and will allow us to add some
cleverness to the device list to allow the FuDevice to be shared between
different plugins.
