Summary

Remove the legacy response handler as a response handler. It will keep the class since it's used in more places as a utility (mainly table vis expression function and the vislib response handler). As soon as we have the new table implementation we can move that over as a pure utility function to the vislib response handler.

Checklist

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• [ ] This was checked for cross-browser compatibility, including a check against IE11
• [ ] Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• [ ] Documentation was added for features that require explanation or tutorials
• [ ] Unit or functional tests were updated or added to match the most common scenarios
• [ ] This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
• This includes a feature addition or change that requires a release note and was labeled appropriately

Dev-Docs

Remove legacy response handler

Remove the already deprecated legacy response handler for visualizations. See Kibana Plugin API changes in 6.5 for more information.