Reduce number of docs in test for #4093 - 30 docs are enough to trigger the bug
Add wabisabi to Scala clients.
_default_ mapping not applied when using separate master/data nodes
fixes #4124
Unable to create a nested filtered alias on a dataless master
fixes #4112
Added support for external query in postings highlighter

It is now possible to highlight an external query using the postings highlighter, relates to #3630

Closes #4121