Court stats: incorrect number of cases in progress

[jaybuidl]

Expected: 0
Actual: 12

https://v2.kleros.builders/#/courts/1/purpose

[kemuru]

currently we don't have this value on the subgraph for a specific court. only for all cases across all courts (thats why in the "Cases" section is shows In Progress Cases correctly, but only for all cases across all courts)