Add support for All Groups

[gjermundgaraba]

Original issue: regen-network#74

We need to implement a version of "show all groups." Currently, the UI only queries for groups you are a member of. We need a way for the user to show all groups.

As a start, add a new table to the front page under "Groups" called "All Groups" where we list all groups. The list needs to be paginated with perhaps max 5 groups at a time.

PR to the empowerchain branch.