Add some energy specific types

Author: PeterC1965

src/app/util/basic-types.h

@@ -33,5 +33,8 @@ namespace chip {
 typedef uint8_t Percent;
 typedef uint16_t Percent100ths;
 typedef int64_t Energy_mWh;
+typedef int64_t Amperage_mA;
+typedef int64_t Power_mW;
+typedef int64_t Voltage_mV;
 
 } // namespace chip