Make code unit-testable

[mclang]

Problem

All code is in single src/main.rs file, which:

1. Gets ugly if the project grows.
2. Makes code harder to test.

Solution

• Split main.rs into sensible modules that can be unit tested properly.
• Make your Rust code unit-testable with dependency inversion
• Traits for Kiho API calls?

Maybe directory structure like in amdgpu_top?