Add a parameter to limit the archival of deleted rows by date. That is,
only rows related to instances deleted before provided date will be
archived.
This option works together with --max_rows, if both are specified both
will take effect.
Closes-Bug: #1751192
Change-Id: I408c22d8eada0518ec5d685213f250e8e3dae76e
Implements: blueprint nova-archive-before