[Data plugin] Add configuration property to enable / disable autocomplete

[alexwizp]

Kibana version: 7.7.0

Initial description:
based on https://discuss.elastic.co/t/kuery-autocomplete-enabled-false-on-kibana-7-7-0/234936:

Looks like this setting was removed in Kibana 7.7.0. I also cant find documentation around this setting being removed. A lot of large Elastic installations rely on this setting to keep Kibana performant (not too mention that the auto complete user experience is not optimal). Is there a replacement or rename for this setting we can use? This is likely a blocker for a lot of large Elastic/Kibana installations like ours. Thanks for your help!

** Root cause analysis: **
In #56607 kuery-autocomplete was moved into Data plugin. As a result legacy kuery_autocomplete.enabled option has become unavailable. We should provide a new alternative configuration option to disable autocomplete.

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)