Module imports should eventually be lazy

[DanielRJohnson]

Right now, every plugin and every driver is imported and loaded into memory in Terminal.__init__. This may become a problem down the road. It's hard to imagine a time where someone could run out of memory since there are only so many forms of data products and data storage types, but it could slow down Terminal.__init__ by having to import and load hundreds of modules. A better practice would be to use lazy module importing and defer loading the module into memory until we know it's actually being used.

Here's some Python documentation I found on it:
https://docs.python.org/3/library/importlib.html#implementing-lazy-imports