Port PUP-3388 "Issue Creating Multiple Mirrors in Zpool Resource" to PUP 3.8

This is a new ticket to port the fixes done for PUP-3388 to release PUP 3.8.0

Bug in the mirror property under zpool resource

https://docs.puppetlabs.com/references/latest/type.html#zpool-attribute-mirror

mirror => ["disk1 disk2", "disk3 disk4"],

In the Previous version It took that string value as a single array and tried to find a drive named "disk1 disk2" and also wouldn't attach the word mirror to "disk3 disk4"

risk: medium
probability: medium (zpool mirror array)
severity: low (work arounds are fairly obvious)
test layer: acceptance