Rearrange Packet Processing into unique states

[ubcheema]

We need to rearrange code in fvc_producer_state so that we do not perform the same checks on a packet repeatedly.
fvc should maintain state and implement state machines in firmware so that we only execute the directly relevant firmware in any given state.

To start, process_inbound_packet() and pull_data_from_fvc_buffer() need to be optimized.

General Plan:
Need array of function pointers that point to different state handlers.

state_handlers[num_states] = {state_1_handler, state_2_handler, ...}

Firmware starts in idle state, and switches to different states based on packet processing state.

The state handler call looks like:

state_handlers[current_state]()