It's actually quite hard to build a front-end for fwupd at the moment
as you're never sure when the progress bar is going to zip back to 0%
and start all over again. Some plugins go 0..100% for write, others
go 0..100% for erase, then again for write, then *again* for verify.
By creating a helper object we can easily split up the progress of the
specific task, e.g. write_firmware().
We can encode at the plugin level "the erase takes 50% of the time, the
write takes 40% and the read takes 10%". This means we can have a
progressbar which goes up just once at a consistent speed.
The end year is legally and functionally redundant, and more importantly causes
cherry-pick conflicts when trying to maintain old branches. Use git for history.
Quite a few plugins use HID commands to communicate with the hardware. At the
mement we have ~6 implementations of SET_REPORT and are soon to add one more.
Move this into common code.
