Dark Sky Sensor didn't expose conditions for day 0 (today forecast) that
had the same name as current conditions. With this change all conditions
form day 0 (today) forecast are exposed the same way as conditions for
the rest of the days (1..7): as `dark_sky_<condition>_<day>`. As a
consequence, conditions for day 0 that were already exposed now have
`_0` suffix. This actually improves the code by removing most of
special handling, based on condition name.
To get day 0 conditions the user now has to add `- 0` to `forecast`
configuration parameter.
Conditions, for which suffix `_0` appeared: `precip_accumulation`,
`temperature_high`, `temperature_low`, `apparent_temperature_high`,
`apparent_temperature_low`, `precip_intensity_max`, `moon_phase`.
This is a breaking change!
Closes#18205
01953ab46b