Add a status API that returns monitoring-relevant information

[pozylon]

• Amount of work items created, grouped by current status
• Amount of orders created, grouped by status
• Amount of events created

And show those numbers:

• For Today
• Since Start of Instance
• Since Ever

[pozylon]

@Mikearaya can you prepare that and make it available to admin users? it should be a rest endpoint like a healthcheck but report that data as json.

[pozylon]

Initially I just wanted a very dumb healthcheck style report but your PR opened this up and I think we can extend it to provide very basic analytics