Upon restarting the upstream VLI USB hub the cxaudio device re-enumerated okay
but would not service HID requests for 100ms, returning 'endpoint stalled'.
To make this more reliable retry the SetRequest up to 10 times after a short
delay to make enumeration reliable.
Quite a few plugins use HID commands to communicate with the hardware. At the
mement we have ~6 implementations of SET_REPORT and are soon to add one more.
Move this into common code.
If we say that the version format should be the same for the `version_lowest`
and the `version_bootloader` then it does not always make sense to set it at
the same time.
Moving the `version_format` to a standalone first-class property also means it
can be typically be set in the custom device `_init()` function, which means we
don't need to worry about *changing* ther version format as set by the USB and
UDev superclass helpers.
