Add a way to fetch the latest hiscore entry for multiple players

[FreekMencke]

This will be necessary for the XP Tracker player widgets. Where we can see how much overall XP our recent and favorite players have earned today.

We can create new lambda function, or update osrs-tracker_player-hiscores to also accept GET /?usernames= besides GET /:username.

TBD

[FreekMencke]

Change this to fetch multiple players at the same time. We added an a query param to include the latest hiscoreEntry to a player-info call.

So we just need to make a call where we can query multiple players (max 10).

[FreekMencke]

Not necessary for now. Will look at it if it's needed.