cleanup root.go

[GrantBirki]

The internal/cmd/root.go file is getting quite long and messy. This issue tracks work to cleanup that file while maintaining the existing functionality and features.

Ideally, all of the code around "displaying" tables, json, and plain text output (the new --output feature), should be moved out to new files. Once in those new files, some extremely simple unit tests should be written against their core logic to ensure they work in the future.