story(rest): implement record event api

[Zaba505]

Description

As an end user, I want to record event using a RESTful API, so that I don't need to introduce a new tech (gRPC) to my existing stack.

Acceptance Criteria

• RESTful route is defined for recording events
• Should accept cloudevents as JSON request body
• Should record events to the backing eventstore
• Should return a "204 No Content" as long as the event is successfully recorded in the backing eventstore
• In case of failure, an appropriate code along with an JSON response object should be returned

Related Issues

• depends on: story(rest): rough out base service implementation #36