story(cmd/serve/dashboard): run dashboard service

[Zaba505]

Description

As a consumer, I would like to have dashboard, so that interacting with evrys for doing things like manually publishing an event can be done from a browser.

Acceptance Criteria

• Dashboard service is serving on provided address from flag
• Should shutdown is CLI context is cancelled
• Should return error from Dasboard service

Related Issues

• depends on: story(dashboard): rough out base http server #49