Warnings regarding the input data

[trotsiuk]

Many users are reporting the unreasonable model output (e.g. #88, #86).

This is mainly due to the fact that the input data are rather un-plausible (e.g. climate, parameters, ...). It would be worth to include more checks and warnings as previously already suggested (e.g. #73, #8).

To include:

• Check wether climate data are outside of the hard ranges
• Check wether site data are outside plausible range
• Check wether species data are outside plausible range
• Warn when the default parameters are used (different species e.g.)
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