Phase out star import use in ocelot

[st-walker]

It's bad Python to have from x import * everywhere. We should slowly remove this from the modules and replace with the equivalent correct explicit imports. This is what I think. What do you think experts?

Reasons:

• static analysis doesn't work with from x import *
• import order may matter without expecting it. in at least one area in ocelot you need to import the modules in the correct order to get desired behaviour.
• namespace pollution is bad
• harder to read code with star imports