Mapping the State Pattern to a Database

Hi, I really like this pattern. But I am wondering how this might work with EF Core. The `Policy` class could easily be an entity that maps to a DB table. But I'm not quite sure how the private nested `State` classes should be handled? Would they live in-memory or in the DB? I can imagine a `State` table containing all possible states that would then be included in all `Policy` queries. But I'm not sure if that breaks this pattern. You are new-ing up the states in the Policy class constructor etc.

No file or test is named. Start by reading the Policy class and its private nested State classes, then inspect how the project currently models persistence; the issue would need a decided EF Core mapping approach and corresponding documentation or implementation before completion can be verified.

Written by the indexing model from the issue text.