Added test with awaits annotation that exposes a merge mapping issue.

 If the path_type is set to `just_name` in a multi_field typed field and that field is updated (for example another multi field is added) then if the path isn't specified again the path_type isn't taken into account and full path names are generated.
Remove ancient `engine.robin.refresh_interval`

Closes #4706
Add missing #setBreaker setter to NodesStatsRequestBuilder
Encapsulate Operations on SegmentReader in a utils class

This commit adds support to extract SegmentReader instances from
FilteredAtomicReader instances to support reader wrapping in
caches as well.
Fix RandomExceptionCircuitBreakerTests

RandomExceptionCircuitBreakerTests never actually installed
the FilteredAtomicReader that should throw random exceptions
when field data is loaded.
ensure open on SegmentReader
add assert to fail if FilteredAtomicReader#in can not be loaded
add comment for random logic in RandomExceptionCircuitBreakerTests
organized imports