UI: Display Events registered by application

Each application exposes different events to react to external signals. User should be able to get http hook URL for each event.
I propose to have a tab on Environment page and inside each application details page. On Environment tab all events from all applications will be listed. I suggest a table like:
| Application| Event name | Event hook URL |
| MyApp | onScale | http://muranoapi/events/<env_id>/<app_id>/<signed_id>/onScale |
| MyApp | onUpgrade | http://muranoapi/events/<env_id>/<app_id>/<signed_id>/onUpgrade |
| MyApp | onBackup | http://muranoapi/events/<env_id>/<app_id>/<signed_id>/onBackup |