Accept a callback std::function when registering a control with SlowControlCollection #7
Description
e.g. if you register a control for a voltage setpoint, then when someone changes it, you need to update the hardware.
so you need to know "oh, someone asked to change this voltage, i need to run a command to update the setpoint"
which right now requires polling through all the registered control values and looking for changes.
if you could register a callback, then when the SlowControlCollection gets a request to change a voltage, it could automatically invoke the corresponding 'UpdateVoltage' function.