Fix shape error in calc_rad_long (rad_utils.py)

[WieFel]

Short Description

Fixes the shape issue mentioned in #81.

I am not totally sure if this is the best possible solution, but it solves the error.

Checklist before PR can be merged:

• closes issue ValueError: operands could not be broadcast together with shapes (5,) (10,) #81
• is documented
• Format code with Black formatting
• type hints for functions and methods
• tests added / passed
• Example Notebook (for new features)
• Remove output for all notebooks with changes