Add watchEntities concept for entities that need to change if other entities have changed

[aguillenv]

For context refer to "prevention" section in: https://github.com/iasql/iasql/blob/main/postmortems/004%20-%20Postmortem%20for%20v0.1.3-beta%20TypeORM%20upgrade%20to%20v0.3.x.md

For more context, refer to: #2093

[depombo]

We are only implemented this once we see the need for it in an entity other that RegistedInstance right? That was my understanding from the RFC

[aguillenv]

We are only implemented this once we see the need for it in an entity other that RegistedInstance right? That was my understanding from the RFC

indeed