Move the channel state management outside the channel implementation.
This simplifies the channel implementation but forces users of the
channel to manage it's state manually.
Add handling for error states in vrtsim which allows to close the
softmodems with CTRL+C without hanging, improving user experience
- Client detection of stale timer.
- Abort state for client and server
This implements a server-client bidirectional time domain IQ channel via
shared memory.
The server creates the channel and should be aware of the client
receiver configuration (num rx/tx antennas).
Server shall be the time source and should call shm_iq_channel_produce_samples
at regular intervals