* hook up restore end-to-end
Now that GC and KW both provide restore operations for a
single message, we can hook up the end-to-end restore
process. Integration tests for this change will follow in the
next PR.
Adds the RestoreOperation to the /internal/operations pkg.
restoreOp.Run() is a no-op at this time since data layer
packages are not prepared to hook up e2e.