WEB: add some interesting stats to other parts of the Court page, like `expectedRewardPerPnk`, `votesPerPnk`, `disputesPerPnk`

[kemuru]

WEB: add some interesting stats to other parts of the Court page, expectedRewardPerPnk, votesPerPnk, disputesPerPnk.

related to #1671 in the sense that the logic for calculating these values can be reused from there, since its already done there, but should be treated as a separate issue and PR

[jaybuidl]