Add Relational Database for persisting raid stats for a user

[dvillavicencio]

This issue tracks the progress for implementing a way for persisting raid stats for a user when they authorize the application. That way we can initially load all the relevant raid info for a given user and then call upon it on a scheduled basis to check for any updates. An example could be in an interval of 30-minutes for each user that uses the bot.

• [x] Create a flyway migration script for creating the initial database tables that will hold all relevant-raid info
• [x] Create repository interfaces and implementations as well as entity classes that represent user-raid data
• [ ] Modify the authorized command to index all the relevant raid information into the corresponding tables
• [ ] Modify the authorized command to index user data and destiny 2 characters into the corresponding tables
• [ ] Create a scheduled job that runs every (TBD) intervals to check for new raids to index for a user

[dvillavicencio]

Closing because of a design choice on not utilizing a persistent datastore. Instead we'll leverage WebFlux's capabilities to serve data without persisting it, and we'll also halt on doing authentication-based commands for now.