Refactor `ackgenconfig` into 2 categories: Generate & API Inference

[brycahta]

Summary

ackgenconfig is used and implemented in a variety of ways throughout the code-generator codebase. Due to this dispersion and inconsistency, it is becoming increasingly difficult to navigate and contribute to code-generator. The updated encapsulations as a result of splitting ackgenconfig into 2 categories will result in a cleaner, more intuitive codebase to alleviate these concerns.

Context

This is the parent issue to track and implement changes to categorize ackgenconfig. The proposal detailing the approach can be found here.

Implementation

• Move pkg/generate/config/config.go to pkg/config/config.go
• Migrate pkg/generate/config access to pkg/config package
• Align naming and return types for APIs in pkg/config package
• Split pkg/config/config.go into pkg/config/generate.go and pkg/config/inference.go

[jaypipes]

@brycahta spot on. let's do this!