feature: add sendCachedValue ws query parameter (#1022)
feature: add sendCachedValue ws query parameter (#1022)

Add the option to suppress sending of latest values when
WebSocket connects. This can be done with query parameter
sendCachedValues=false. Any other value or no query parameter
with that name results in previous behavior, sending all
the relevant latest values as deltas.
SignalK/signalk-server-node,SignalK/signalk-server-node,SignalK/signalk-server-node,SignalK/signalk-server-node