We're not going to subclass this, and making it final saves during startup:
* 300K calls of fu_progress_get_instance_private()
* 280K calls of fu_progress_get_step_weighting()
Using `sudo FWUPD_PROFILE=10 ./src/fwupd --verbose` will print a
dump of startup times onto the console so that we can debug which
plugin is slowing down system startup. For example:
../src/fu-engine.c:5409:plugins-coldplug [108.55ms]:
../plugins/amt/fu-plugin-amt.c:437:amt [27.14ms]:
:create-context [12.66ms]
:get-version [8.44ms]
:add-device [3.95ms]
This allows us to print better warning strings, and in the future
would allow us to profile each operation in a meaningful way.
Also, add context to some of the progress steps as required.
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.
