Feature: Support batch checking a lot of entities

[dpriskorn]

I would like to check all swedish hiking trails every week and be notified about any items that do not conform to the schema.
I'm considering creating a new react app based on this API

One pain point is downloading of the schema again and again, which I want to avoid.

I would like these new endpoints:

1. an get endpoint to get the schema as json
2. an post endpoint to analyze an entity given the schema json and entity json

This could speed up the process a lot.
WDYT?

[dpriskorn]

I found that accepting a EID and a list of entity IDS would be a better way to do it.