event dashboard endpoints

[grounded042]

We need endpoints for retrieving event stats and responses. The endpoints will all sit behind auth. The endpoints will be as follows:

• GET /events/:id/relationships/invitees
  • get a list of the invitees for an event that includes their responses
  • this MUST be paginated day one. Fetching large numbers of invitees from the database has performance problems and will also need to be refactored for this.
• GET /events/:id/relationships/stats
  • This will return an object with several pieces of data:
  • menu option selection numbers (for each menu item, it has been chosen x number of times)
  • number of invitees
  • number of invitees who have responded
  • number of guests who are attending
  • 5 most popular people to sit at a table with