Add `gds#find`

Based on feedback from @maxdemarzi, introduce a `gds#find` method that replaces `gds#findNodesByLabelAndProperty` and `ggo#getAllNodesWithLabel`.
In addition - if you can think of another `find` that takes three arguments, a Label, a String and an Objects that _isn't_ lookup by label and property+value... I'll buy you a beer :)