* `sql-editor-autocomplete-match-style` options for perf

Large instances with 100ks of fields are choking on the select name from
fields where name like "%search-term%`. Version in 43 was
acceptable. This adds back the behavior in 43: prefix searching.

Also adds ability to turn off if even the prefix search is burdensome.

* Rename autocomplete-suggestion param `search` -> `substring`

* support sql-editor-autocomplete-match-style on the FE

* fix substring shows placeholder

* Ensure using prefix style matching in e2e test

* Make autocomplete style public

* Rename defsetting to have "native-query" in name, not sql

generally true. Consider mongo which has a native editor but no notion
of SQL

Co-authored-by: Aleksandr Lesnenko <alxnddr@gmail.com>