n-gram matching support in streaming mode

[Alexander-Mark]

Is your feature request related to a problem? Please describe.
When setting gram matching in a field of a doc that uses streaming mode, the following warning is given:
n-gram matching is not supported for streaming search

Describe the solution you'd like
For streaming mode to support n-gram matching.

Describe alternatives you've considered
We are using substring matching in streaming mode as an alternative.

Additional context
Fuzzy search would be nice to have in those cases where high recall (eg misspellings) or CJK search is a priority in apps using streaming mode.

[vekterli]

We changed the title to remove "fuzzy" for disambiguation since streaming search already supports the fuzzy matching query operator in both regular and prefix match modes. Since you're currently using substring matching as an alternative I presume your use case is for fuzzily matching a term within a longer string (as opposed to fuzzily matching full strings)?

Having streaming search feature parity for n-gram matching definitely makes sense (especially for CJK, as you mentioned), but I'm not sure when we'll have time to look at it.