708: Refactor projection actor before adding new functionality r=klochowicz a=klochowicz
Create watch channels within the actor, returning a single struct called `Feeds`.
Manage the struct with Rocket and use it in SSE events.
Changing the watch channel types etc. will be much easier after this cleanup.
Co-authored-by: Mariusz Klochowicz <mariusz@klochowicz.com>