When restoring a database, people would encounter errors if
the restore happened after telemetry has run. This is because
a 'exported_uuid' field would then exist and people would encounter
a "duplicate key value" when the restore tried to overwrite it.
We fix this by moving this metadata to a different key
in pre_restore and trying to move it back in post_restore.
If the restore create an exported_uuid, that restored
value is used and the moved version is simply deleted
We also remove the error redirection in restore so that errors
will show up in tests in the future.
Fixes#1409.
These functions improve usability and take all the proper steps to
set restoring on/off (and stop/start background workers in the process)
and to set the license key via a function rather than a guc modification.
