Packet support should include an implementation of a variable size packet (uplink)

[mudinthewater]

This is typically used for string arguments for commands that may be inconsistently-sized.

An example would be a command that exists to echo a string sent in uplink down as an evr - a "we are here" type command, or a command that executes an arbitrary FSW function.

[cjjacks]

A string or byte array type of definite size might be useful for downlink as well