[Breaking] [data.autocomplete] - Migrate core kibana autocomplete configs to data plugin

[lukeelmers]

Per the discussion in #46705, we need to migrate some of the yml config options which were previously part of the kibana plugin into data, where it makes more sense for them to live.

• kibana.autocompleteTimeout -> data.autocompleteTimeout
• kibana.autocompleteTerminateAfter -> data.autocompleteTerminateAfter

Note that the long term plan is to rename everything to snake_case (as discussed in #7444, this is something we would do all at once instead of incrementally). But for now we should rename to camelCase, and address conversion to snake case whenever that larger PR is put together.

[elasticmachine]

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

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[alisonelizabeth]

Hi @lukeelmers! In terms of how the Upgrade Assistant can help here, I think we could check for the existence of the deprecated settings and provide a code snippet with the replacement names. WDYT?

We also now have a 8.0 breaking change issue template that might be helpful to take a look at to provide additional context.

[lukeelmers]

I think we could check for the existence of the deprecated settings and provide a code snippet with the replacement names. WDYT?

Thanks @alisonelizabeth! Yep I think a check like that would be just fine. We might have some other config names we are changing too, I'm taking a look at that and will let you know if there are any more to add.

[alisonelizabeth]

I'm going to remove the Elasticsearch UI team label. Going forward, deprecations should be registered by the plugin owner via the core deprecations service (#94845). All registered deprecations will be displayed in the Upgrade Assistant (to be implemented via #97159). Feel free to reach out to myself or the core team with any questions!

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)