All packages follow STYLE.md guidelines

[rmvangun]

This is a very large PR that refactors all packages to follow the STYLE.md guidelines. This refactor involved:

• Standardizing comments and headers
• Scoping shims to the object vs. the package
• Consolidating test setup in each package to follow a more unified approach
• Some modernization to suit recent Go versions
• Using real config handler and dependency injector in tests so they don't have to be constantly mocked

A couple of small functional refactors were additionally required, including:

• Adding omni to .gitignore
• Including registry URL in the config merge/copy functionality
• Removal of InitializeComponents in main.go
• Reducing minimum versions allowed by tools

[rmvangun]

Task linked: ENG-330 Test Refactoring / Cleanup