Improve random tests for text/keyword multi-fields #131865
Description
text and keyword fields can have multi-fields of other types. When such a multi-field exists and synthetic source is used, we try to only store either the parent or child field to reduce disk usage. This has resulted in some recent bug: #131298
It would be nice to have some more random test coverage over text/keyword fields with multi-fields. Ideally, this coverage should have found the bug if it existed.
Tasks:
- Add ability to make term/phrase queries over the randomly generated fields. Currently, queries are static and used fields that are known to exist in the docs. Add random queries to logsdb data generation tests #132109
- Add multi-fields to random test generator. Some work already done on this: Add random tests with match_only_text multi-field #132380