Helper function to get an array of PacketWithPayload(s) to transmit the payload_bytes
this function splits the payload_bytes into 80 byte chunks and orders them appropriately for
Poly phone consumption
Public function to get a single payload packet as an array of bytes.
Takes the payload as a [u8; 80], aka, an 80 byte array
Must also include the last chunk of payload. On the first packet, the last_chunk must equal the payload_chunk
Helper function to get an array of another array of bytes, from get_payload to transmit the
actual packets rather than the internal representation of an array of PacketWithPayload(s)