allow sensor type selection per plant, changed calculations to use PCT values, due to different raw value meaning

esp32/src/MathUtil.cpp

@@ -4,4 +4,9 @@
 bool equalish(double x, double y)
 {
         return (abs(x - y) < 0.5);
-}
+}
+
+double mapf(double x, double in_min, double in_max, double out_min, double out_max)
+{
+    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
+}