Added a schema validation for backup and restore CR. Also validating
the server address in the backup/restore controller.
Validating the server address as :
^([0-9]+.[0-9]+.[0-9]+.[0-9]+:[0-9]+)$
which is :
<any number>.<any number>.<any number>.<any number>:<any number>
Here we are validating just the format of the IP, not validating that IP should be
correct which will be little more complex. In any case if IP is not correct,
the zfs send will fail, so no need to do complex validation to validate the
correct IP and port.
Signed-off-by: Pawan <pawan@mayadata.io>