Refactoring + support for who icd10 codes

Following updates:

• Major refactoring and code clean up of CLI
• Split into two mains:

1. main_trinetx.go for building CLI for bladder user case (from the paper)
2. main.go for building a more generic CLI for new use cases

• Added dot graph generation
• Added quality metric based on modularity scores
• Added structured logging

First release

Original code as in the paper.