L2SS-244: Add calculator for what the packet size should be, which helps feeding them from a continuous datastream (like disk).

L2SS-244: Renamed SST->SST_collector to avoid name clashes elsewhere. Expose all collected values in our SST device

L2SS-244: Just collect values per input. They should line up, but they may not, and this way we can detect that.

L2SS-188: Renamed statistics_device -> Statistics, as it's a name, and it's a device per definition.

L2SS-192: reserved_0 -> reserved to not be overly defensive. if there are multiple reserved fields in the future, we'll deal with that by then.

L2SS-192: Provide interface for raw header fields, add example packet (needs to be a better one, but this is all we have for now)