Full prefix: satellite/{overlay,nodestats},storagenode/{reputation,nodestats}
Allow the storagenode to receive its audit history data from the
satellite via the satellite's GetStats endpoint.
The storagenode does not save this data for use in the API yet.
Change-Id: I9488f4d7a4ccb4ccf8336b8e4aeb3e5beee54979
* Separate audit history interface into its own file in the overlay
package
* Add overlay.AuditHistory struct so that internalpb.AuditHistory is
only used from within the database layer
* Add overlay.GetAuditHistory function for features that will require
access to detailed audit history information
* Do not return full audit history from UpdateAuditHistory - callers to
that function only need to know the online score and whether a full
tracking period has been completed
* Move audit history tests out of satellite/satellitedb, since they are
independent of database implementation
Change-Id: I35b0c4ac23bbaabd80624f8a9631c3cb1a1f33bd
