Usage details for event in month

Report with used seats for an event in a month.

GET /reports/usage/month/{month}/event/{eventId}

E.g. /reports/usage/month/2018-09/event/32429

[
{
"object": "A-1",
"numFirstBookings": 1,
"firstBookingDate": "2018-09-13T00:16:43.176Z",
"numFirstSelections": 0,
"numFirstBookingsOrSelections": 1
},
{
"object": "A-2",
"numFirstBookings": 0,
"firstBookingDate": "2018-09-13T00:16:43.176Z",
"numFirstSelections": 1,
"numFirstBookingsOrSelections": 1
},
{
"object": "Standing",
"numFirstBookings": 34,
"numFirstSelections": 56,
"numFirstBookingsOrSelections": 56
}
]