Replace admin/editor boxes with dropdown

Created by: philmcmahon

This is a follow up from https://github.com/aptivate/econsensus/pull/157 for this ticket: https://aptivate.kanbantool.com/boards/5986-econsensus#board-view

Hopefully it's okay now! Also added a back to your organizations link to the new 'admin' page for an organization.