Is your feature request related to a problem? Please describe.
Per week we can receive two pieces of loot while opening weekly caches (there are various types of caches) and four Restored Coffer Key (used to open delves chests at the end)

Example of one of these caches: https://www.wowhead.com/item=224784/pinnacle-cache

There's no clear way of tracking this right now.

Describe the solution you'd like
I would like a counter somewhere in SavedInstances that would track how many caches we obtained/opened per week.

Something like "Weekly TWW caches: 1"

Describe alternatives you've considered
There is a weakauras by Tama (https://wago.io/TamasTheWarWithinHelper/47) that tracks this, it will show "Weekly World Quest caches x2 X/X", but I don't like having this always showing in the screen.

Thanks for the link, I'll test the implement later today, and make a pr if it works well.

For looted Restored Coffer Keys tracking quest id's are 84736-84739, this could also be just for cache opening, hard to tell as those are happening at same time, so who knows...

Tested last day and found the quest ids provided by the WA (83280, 83281, 82582, 88738) fails to provide correct progress. I'll try new quest id here.