Create Point3d from tuple and list.

[rodja]

This PR adds two helpful builder functions to the Point3d class.

[falkoschindler]

What do you think about this alternative?

@staticmethod
def from_sequence(seq: Sequence[float]) -> Point3d:
    return Point3d(x=seq[0], y=seq[1], z=seq[2])

I'm not too sure about the name from_sequence. But we could call it from_tuple (referring to the already existing tuple property) and accept a Sequence[float], so that you can use it for tuples and lists.

[rodja]

@falkoschindler I like the idea to consolidate the factory with Sequence. I've also added a docstring. Ready to merge?