[Sketch] Server population API endpoint

[leonhard-s]

The following are unsorted notes on the population tracking API. This is not worked on right now, so this only acts as a reference for later.

Activity levels

• Logged in (login and logout events, 3 hour activity timeout)
• Active (check gainexperience events or logout, must be active in the last 15 minutes)
• Fighting (gainexperience stream only, has died or killed within the last minute)

Scopes

• Global (all servers)
• Per server
• Per continent
• Per facility (deferred)

Miscellaneous

• Track current faction for NSOs (deferred until TeamID is finally added and not busted)
• Provide all views for both faction (i.e. NSO/TR/NC/VS) and alignment (TR/NC/VS, all including their NSOs)