restore: Handle FDRTrustData request messages

Only send an empty reply but this seems to be enough to restore
devices that already have valid data.
tss: Intercept server status code 126 indicating malformed request
tss: Make ApECID key mandatory and also use it for baseband TSS requests
Rename restore step to indicate flashing of firmware instead of NOR
Do not link with libusb manually as libirecovery dependency already adds it