wnd_dir column fix

[moritzshore]

This change makes it so that only columns to weather_sta_cli are written which also exist in the database.

This is a fix for an issue I encountered due to SWATprepR trying to write wnd_dir data into my SWAT+ DB, even though my DB did not have a column for wnd_dir.

pet was also missing from the SWATprepR list.

Versions used:

• QSWAT v4.0.1
• SWAT+ Editor v4.0.1

Probably this is due to the new versions?

I would not merge this yet! I have not tested this yet with the older versions of SWAT+, so it may be breaking to those, which would mean some extra code should be written to make this backwards compatible? perhaps only adding PET if it also exists in the DB? Mainly just posting this PR to bring your attention to it. Might test it on older versions if I have time, but please feel free to modify.