Add type annotations to python files

[cschindlbeck]

Since moveit2 targets python3, have type annotations been considered? I would do it if there is interest and no one is opposing this idea, or is python2.7 still supported?

[AndyZe]

Hi @cschindlbeck,

I don't have a strong opinion on the idea of type annotations.

I'll just note, there is a lot of dead Python code in MoveIt2 right now. moveit_core, and moveit_commander have some unused Python files, for example. So don't spend any time on those. Best to ask here before jumping in to a specific package.

Python 2.7 is not still supported.