Add Geo changes to audit events

As part of audit events, we should log all instance-level changes in the admin panel.

We should track additions/changes to Geo nodes on an instance:

  1. Node create/updates
    • URL
    • Primary node?
    • Selectively sync projects
    • Repo sync capacity
    • File sync capacity
  2. Node removal
Edited by Jeremy Watson (ex-GitLab)