Don't error when search finds no results

Problem/Motivation

JsonApiClient::search() raises an error when no search results are found.
This is not an error condition. It shouldn't even be logged.

Steps to reproduce

Search for something that doesn't exist. Check logs.

Proposed resolution

Remove raising of error log.

Remaining tasks

All the things.

User interface changes

None.

API changes

None.

Data model changes

None.