Design: Node Registration

## Description

Design flow of node registration

## Breakdown
- Data structure needed
- Flow chart
- Transaction structure (Tx body)

## Reference

for details see: https://docs.google.com/document/d/118CdR0WOIpZx4C9Hnx-JsrHz3vXn9OZ6eMokk9y71hk/edit?usp=sharing