Hide DKG rituals involved on DKG heartbeat rounds

The use of DKG heartbeat rounds is flooding tacoscan with DKG rituals that probably are not of the interest of actual users, but only for us to monitor nodes.

These DKG rituals are expected to have a size of 2 or 3 participants, so a quick way of filtering could be to show only rituals with participants lenght > 3.

We also could have a checkbox that activates/deactivates this filter.