Improve type support error message (#117)
Improve type support error message (#117)

* refactor type support import + check and raise better error message

* actually wrap the call

* should we wrap the second one knowing that the first one throws?

* check only attribute in wrapping + talk about workspaces and not PYTHONPATH

* modify existing exception rather than raising a new one

* clarify message

ros2/rclpy,ros2/rclpy