Validation failure messages should mention that they are related to Elasticsearch schema validation

Description

Currently the failures only mention the type, field, etc., but never mention that they are related to automatic schema validation, which is kind of confusing (e.g. here)

We should probably insert a context element below "type", something like this:

Alternatively, we could insert a failure message before anything else:

Environment

None

Assignee

Yoann Rodière

Reporter

Yoann Rodière

Labels

None

Suitable for new contributors

None

Feedback Requested

None

Components

Fix versions

Affects versions

Priority

Major
Configure