MessageStoreCache tests specific for caching search results.
MessageStoreCache tests specific for caching search results.

Tests get_query_token() for consistent tokens with dictionaries.
Tests start_query() to see if `is_query_in_progress()` works
Tests store_query_results() to see if we receive results in the correct
order.

harrissoerja/vumi,TouK/vumi,TouK/vumi,vishwaprakashmishra/xmatrix,TouK/vumi,harrissoerja/vumi,vishwaprakashmishra/xmatrix,vishwaprakashmishra/xmatrix,harrissoerja/vumi