Filter hotspot reward transactions by type

[tyler-whitman]

Currently for hotspot activity we have a filter type for rewards. In the app we use that filter type to pull hotspot rewards and then we have to filter further for poc_witnesses rewards or data_credits rewards.

This is used for the hotspot checklist currently and more features are planned that will need specific hotspot reward types.

The problem with this is that for example for hotspot checklist if we need to get a recent data_credits reward we have to keep pulling pages of hotspot reward items until we find one with a data_credits item in it.

If we were able to filter hotspot rewards by a filter type such as rewards:data_credits then we could just pull the first element and know when the last activity of that specific reward type was.

[cokes518]

include validator reward transactions by type (CG rewards, eventually challenge creation)