feat: add result cache consumer

[Willem-J-an]

Attempt to solve #195.

Need some feedback: the client interface does not seem to expose any way to update results. Any pointers on how to solve this? I have some ideas but not super happy with them:

1. The client exposes a method to update_results; might expose too much internals to consumers
2. The client exposes a method to load results from cache (as done now); bit weird because it's logic only my consumer needs, but arguably exposes less internals.

[Willem-J-an]

@rcarriga any feedback on this? Thanks!

[rcarriga]

Thanks for the PR! Overall love the idea, just some minor fixes/changes. I also think this would make sense as part of the state consumer and in the state consumer config we can have something like persist_results: boolean, rather than a whole separate consumer for it. It can still be a separate module to keep it tidy

[Willem-J-an]

Thanks for the PR! Overall love the idea, just some minor fixes/changes. I also think this would make sense as part of the state consumer and in the state consumer config we can have something like persist_results: boolean, rather than a whole separate consumer for it. It can still be a separate module to keep it tidy

I have added a config to auto load cache on startup; not sure now what functionality you would expect from a persist_results boolean. It should automatically cache all results as soon as they come in; rather than having to execute a command to cache it?