* Add native unit types for weather entities
* Update weatherentity and change precision in climacell test
* Move weather test to demo tests
* Add weather test for temperature conversion
* Add more unit conversion tests
* Remove extra native_ methods
* Remove extra properties and save precision change for another PR
* Remove visibility_unit from metoffice component
The vibility values given by metoffice are formatted into strings,
which means they can't automatically be converted.
* Improve docstrings and convert pressures in forecast
* Add precipitation and wind speed units
* Clean up tests
* Round converted weather values
* Round weather values to 2 decimal places
* Move number of rounding decimal places to constant
* Docstring and styles
