cluster validators by entity

[tomerweller]

As more validator nodes join, the list becomes cluttered.
I propose clustering the nodes by entities - like "ibm" and "sdf"
Then instead of showing a list of nodes, we will show a list of entities - each one summarizing all of the entity's nodes.

[chriserice]

+1 to the Group by (and sorted by) entity name idea. The 5/21 update to include host names column will differentiate nodes within the group.

[bartekn]

We started displaying nodes in a random order (you can also order alphabetically but random is default) and added pagination. I think this solves the main issue here which was long list of nodes.