How to prevent PV input to charge controller if battery breaker trips
I'd make the battery breaker a double and use one side to feed a relay on the solar lines, maybe solid state to make it fast and low drain on the battery. As shown below. The reason for the ganged breaker is I am not sure what the output of the controller will do when the breaker opens. It may still drive out a high voltage for a while before it dies...







simulate this circuit &ndash; Schematic created using CircuitLab

You need to chose a relay that has a coil/activation  voltage that is the same as your battery voltage, and can carry the current expected from the solar panel.

Potential issues: 
1. Hopefully the controller is robust enough to handle the switching time. 2. If the batteries drain too much the relay will drop out.

Alternative would be to "gang" the battery and solar breaker so you can not turn off one without the other. But that will not protect you from a battery disconnect, intentional or otherwise.