Move Non-Canvas methods out of nipyapi.canvas module

[Chaffelson]

During the early development of NiPyAPI, many methods landed in the canvas module which are not actually canvas manipulating commands. They were kept there along with newcomers to avoid breaking backwards compatitbility but at the cost of bloating the canvas module.

With the 1.0 release Controller calls, and some other non-canvas calls, will be moved to their own module as good housekeeping to stop Flake8 nagging me.