[APM] Add test to ensure that search bar suggestions work across spaces

[sorenlouv]

Recently there have been a couple of regressions that affected the ability to use the search bar and see suggestions. In one specific case the field suggestions worked in only one of the spaces (the first to be opened) but not in subsequently visited spaces.

Solution
We should have an e2e test that ensures that the list of field suggestions can be displayed in at least two separate spaces.

Related:

• [APM] Suppress error toast when data view cannot be created #143639
• [APM] Fix search bar suggestions #141101
• Prefer DataView client over SavedObjects client when possible #136694

[elasticmachine]

Pinging @elastic/apm-ui (Team:APM)