Soil Sensor API

[David032]

• [x] Get Soil Moisture Value
• [x] Is active?
• [x] Is new data available?
• [x] Get Saturation
• [x] Get History
• [x] Set wet point
• [x] Set dry point

[David032]

Test results:

• The input var should be looked at again at some point - Sensor 1 is on pin 23 which is the 2nd element in the list