Dispatch single binary (#549) * Add `dispatch-server` binary, which can run most Dispatch services locally. Uses docker daemon as Function and Image backend. * Adds Entity Store-only secrets backend. * Adds in memory backend for event subscriptions. * Adds Docker backend for functions manager. * Adds flags to Image Builder to control push/pull to/from image registry. * Adds a HTTP server wrapper that handles multiple services and multiple listeners. * Added an all-in-one router that is able to route to different dispatch services using http.Handler * Fixes a bug in Event Manager where subscriptions would be recreated on update even when they don't need to. * Cleans up some of the unnecessary logging |