This allows us to 'nest' firmware formats, and removes a ton of duplication.
The aim here is to deprecate FuFirmwareImage -- it's almost always acting
as a 'child' FuFirmware instance, and even copies most of the vfuncs to allow
custom types. If I'm struggling to work out what should be a FuFirmware and
what should be a FuFirmwareImage then a plugin author has no hope.
For simple payloads we were adding bytes into an image and then the image into
a firmware. This gets really messy when most plugins are treating the FuFirmware
*as* the binary firmware file.
The GBytes saved in the FuFirmware would be considered the payload with the
aim of not using FuFirmwareImage in the single-image case.
Devices may want to support more than one protocol, and for some devices
(e.g. Unifying peripherals stuck in bootloader mode) you might not even be able
to query for the correct protocol anyway.
At the moment FuChunks are sometimes mutable, and sometimes immutable, and it's
all a bit too low level for comfort.
Before we can do any kind of optimisation or verification we need plugins to
stop reading directly from the C structure. The aim here is to make FuChunk
optionally mutable without making assumptions about the memory model, and also
to be able to introspect it for the docs.
This is not complete enough for LVFS-usage, but good enough to use with commands
such as fwupdtool. It's likely newer kbd and tp firmware will be required to
integrate with the fwupd in all required ways.
