Overridable Vertx components

[plyhun]

Abstract

A mechanism allows having the default core components overridable by the alternative server implementations.

Checklist

General

• [ ] Added abstract that describes the change
• [ ] Added changelog entry to /CHANGELOG.adoc
• [ ] Ensured that the change is covered by tests
• [ ] Ensured that the change is documented in the docs

On API Changes

• [ ] Checked if the changes are breaking or not
• [ ] Added GraphQL API if applicable
• [ ] Added Elasticsearch mapping if applicable