This allows several things, for instance:
* Adding or removing blacklisted plugins or devices
* Changing the idle timeout where allowed
...without a user needing to manually modify a configuration file.
The offline updates environment is special, and we have to be careful to delete
the trigger before doing anything that can fail to avoid boot loops.
For this reason, split it out to a simple self-contained binary that is easy to
understand.
This is intended for devices that it is not safe to immediately activate
the firmware. It may be called at a more convenient time instead.
Both fwupdmgr and fwupdtool support the feature.
- if called at runtime with fwupdmgr it uses the daemon
- during shutdown fwupdtool uses the pending.db to perform this feature.
