Typing improvements

[jhamon]

Problem

The more type hints we have in our package, the better people will be able to understand how to use it.

Solution

Much of the untyped code in the package is derived from old generated code that we have extracted. So there's a fair amount of refactoring in this difif to try to break out some smaller classes and functions with seams that you can start to analyze and type; when everything is just big mutable state blobs it is quite hard to reason about.

Along the way I uncovered that bulk import features were in a broken state because some of those operation ids was modified since the last release and these functions are not well-covered with automated tests. This sort of thing really highlights why we need better type coverage in the package.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• None of the above: Refactoring to improve type safety