Remote CAN network monitor GUI (à la EasySetup)

[PeterBowman]

YARP provides an ICanBusErrors interface to access several CAN network-related parameters stored in a CanErrors structure. It is yet to determine their purpose since no documentation is available, but here they are:

• txCanErrors
• rxCanErrors
• busoff
• rxCanFifoOvr
• txCanFifoOvr
• txBufferOvr
• rxBufferOvr

The ICanBusErrors interface would need to be implemented by CAN devices, currently CanBusHico and CanBusPeak. In this way, CanBusControlboard could check the network state periodically and watch for RX/TX overruns, network errors and, most interestingly, bus load (having the new PDO implementation in mind as detailed in #223).

Perhaps those parameters are not suitable for the goal of this issue. It is, however, a starting point I'd like to explore. All relevant parameters (per CAN bus) would be presented to users via GUI app (#224).

[PeterBowman]

First attempt at 0867506, not tested.

[PeterBowman]

Note to self: expose simultaneous CAN reads/writes?

[PeterBowman]

We may feel somewhat constrained by the ICanBusErrors interface in that it allows to expose only a subset of available CAN status items (not so surprisingly). See #231 regarding more sophisticated tools; I'm marking this as blocked for said reason.

[PeterBowman]

Actually blocked by #160, which targets streaming CAN data through YARP ports.

[PeterBowman]

Since remote connection to active YARP ports streaming CAN data is desired, keep in mind the following issue raised at #160 (comment) regarding lost packets and YARP carriers.

[PeterBowman]

I'm closing this as invalid. Bus-off state is now monitored as described in #242, CAN bus load is streamed via YARP port thanks to #160, and everything GUI-related will be discussed at #224.