Dual sensors: Direct copy of sensor model type
Functional collection from 2 sensors
Better graph sizing
Fix bug in sensor data collection

It was accidentally emitting data once per data *point* instead of once
per data *sample*.

This only became evident when collecting from multiple sensors at the
same time.
Better dual sensor interactive layout
Dual sensor: Track isSensorTareable separately per sensor
Dual sensor: Only enable the start button if both sensors are selected
Dual sensor: Retain tare values on reset

This fixed a bug in the Datagames environment where a dialog prompted by
reset() was non-blocking, and so the tare values weren't correctly being
retained.
Dual sensor: Fix missing reading values
Dual sensor: Stack sensor selection vertically
Dual sensor: Remove graph titles and readjust layout
Dual sensor: Can tare each sensor separately