Add minimum and maximum temperature to Met.No weather integration

Feature Requests
1

This could actually be easy to implement…

Currently the Met.No integration shows forecast temperature as just the temperature forecasted at 8am on each day. This should show the forecasted minimum and maximum temperatures of each day.

Met.No API call shows minimum & maximum temperatures in 6hr blocks in the following format:

<product class="pointData">
  <time datatype="forecast" from="2020-05-07T06:00:00Z" to="2020-05-07T12:00:00Z">
    <location altitude="70" latitude="60.1" longitude="9.58">
      <precipitation unit="mm" value="0.0" minvalue="0.0" maxvalue="0.0"/>
      <minTemperature id="TTT" unit="celsius" value="7.0"/>
      <maxTemperature id="TTT" unit="celsius" value="13.3"/>
      <symbol id="PartlyCloud" number="3"/>
      <symbolProbability unit="probabilitycode" value="0"/>
    </location>
  </time>
</product>

A sensor type for min & max temperature will need to be added.
Only the highest maximum forecast and the lowest minimum forecast should be shown in any 24hr period.
Example:

00:00 - 06:00:
  Min: 5c
  Max: 7c 
06:00 - 12:00:
  Min: 8c
  Max: 18c 
12:00 - 18:00:
  Min: 12c
  Max: 19c 
18:00 - 00:00:
  Min: 7c
  Max: 11c 
24hr min & max:
  Min: 5c
  Max: 19c

This could all be done in core/yr/sensor.py

Unfortunately I don’t have the appropriate setup to test any code changes I’d make if I were to do it myself.