Determine if it makes sense to include the index id in QueryParamsEvent

Problem/Motivation

If you subscribe to a QueryParamsEvent you can check if the index ID matches what you're expecting. Currently this includes the index prefix, so if your prefix is foo_ and your index is bar the index ID will be foo_bar. This is mostly fine, except the event subscriber has no way to know what the index prefix is, as that is hidden away in BackendClient::settings.

This is mitigated in ✨ Add query object to QueryParamsEvent. Active as you can use $query->getIndex()->id().

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes