Improve search tests with more recreatable search terms - to avoid caching skewing results

Today our search tests test various scopes for the three available levels - Global, Group and Projects. Currently however we test each scope with only one search term. The Search team has advised that caching on Elastic's side may be coming into effect here and affecting the results since it's the same term each time.

As an improvement to this they've suggested bringing in multiple terms instead for each scope and to combine them as various multiword searches. Along with this we discussed though that the term combinations used must be the same each time to make the tests recreatable. Task is to explore this approach and switch to it.

cc @DylanGriffith @ebanks

Edited by Dylan Griffith