Reduce log spamming during night time due to no solar irradiance

[t-ober]

When it is night and no solar irradiance is available we spam the log with warnings:

15:26:51.529 INFO  e.i.s.e.l.RuntimeEventListener$ - ******* Simulation until 2023-02-09T22:45:00Z completed. (duration: 0h : 0m : 0s : 15ms , memory: 3.7 GB) ******
15:26:51.542 WARN  e.i.s.s.weather.WeatherSourceWrapper - Direct solar irradiance not available at POINT (7.65 48.3).
15:26:51.542 WARN  e.i.s.s.weather.WeatherSourceWrapper - Direct solar irradiance not available at POINT (7.65 48.05).
15:26:51.542 WARN  e.i.s.s.weather.WeatherSourceWrapper - Direct solar irradiance not available at POINT (7.9 48.3).
15:26:51.542 WARN  e.i.s.s.weather.WeatherSourceWrapper - Direct solar irradiance not available at POINT (7.9 48.05).
15:26:51.545 WARN  e.i.s.s.weather.WeatherSourceWrapper - Direct solar irradiance not available at POINT (7.65 48.3).

The warning was intended to signify that there is actually no weather in the database but not that its magnitude is 0. We should differentiate those cases.

[t-ober]

Might be related to: ie3-institute/PowerSystemDataModel#554