The only real value of the optionrom plugin is the ability to store and verify
the ROM checksum; parsing the image is not actually required and is a source of
anxiety for various security teams.
This has better multi-core performance and can run in persistent mode -- which
allows us to construct a test harness of all the parsers (which takes time) and
then just reuse the process for lots of different data.
The new plugin is called `optionrom` as this is the only type of image that it
parses for verification only. FuUdevDevice is also the generic parent already.
