As Slapgrid is retrieving the full content of the instance it should
store it so that other recipe can access it directly instead of
querying master

slapgrid: Make json dump consistent when using slaptool

slapobject: dump ip addresses in instance json

slapgrid: update tests to check ip list on instance dump

* Use the same data structure as the rest of the API

This was creating irrelevant validation fails when parsing weird urls