Add checkbox or list of "related" A and/or PTR and/or A+PTR records for allocation delete

[Kris Deugau]

For complex DNS datasets that have been migrated into management tools, there may be dangling A, PTR, or A+PTR records that are related to the IP or allocation. Add a checkbox, or set of checkboxes, to allow requesting deletion of these extra records. Requires matching support in dnsadmin to retrieve any such records.