Provide base implementation of deframer / packet processor

[nttoole]

• ASU has an example deframer
• Deframer should handler processing / reordering of rames and emission of contents
• Packet processing should expect stream of ordered packets and split output in sane way (APID)

[nttoole]

General approach for the design is to create a greenlet server that receives frames from the SLE server (#111) and emits CCSDS packets to the AIT telemetry port. The data-field portion of the frames (AOS MPDU for now), contain a list of CCSDS packets, with the potential for partials in front and the end. These will be collected and partials reconnected. Some logic will be need to handle: 1) gaps or missing packets 2) out of order packets. Modes will be supported to either wait for ALL in-order packets or to move passed dropped packets.