This makes more sense; we're updating the device, not the plugin itself.
This also means we don't need to funnel everything through callbacks like
GFileProgressCallback and we can also update the state without adding an
explicit callback to each derived device type.
This is a large commit that removes all the providers and turns them into
plugins. I think having both providers _and_ plugins was super confusing.
Plugins are loaded at runtime so you could in theory develop a new plugin
without putting it in the fwupd source tree, although there are no installed
headers or PC files as I'm not sure it's a good idea at this stage.
This commit moves all the per-provider docs, tests, notes, debug dumps and test
data to plugin-specific directories -- these also allows the plugin author to
"own" more of the source tree so we don't enforce fu- prefixes and the style
guide everywhere.
This allows us to run the same action on all the plugins in the future, so we
could have a prepare(FuPlugin, FuDevice) and cleanup(FuPlugin, FuDevice) run
on *all* plugins, so doing an update using one plugin would allow us to work
around hardware quirks in other plugins.
If I've broken your out-of-tree provider it's trivial to port to the new API
with sed and a fixed up build file. If you need help please let me know.