Changes to Seed default pages for portal navigation items

added the pattern ^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$ to the request property ids/items

the ids/items request property format changed from no format to uuid

endpoint added