FormatDestination returns the namespace/name format for the destination.
This is different from (*api.Intention).DestinationString in that the
default namespace is not omitted.
FormatSource returns the namespace/name format for the source. This is
different from (*api.Intention).SourceString in that the default namespace
is not omitted.
ParseIntentionTarget parses a target of the form <partition>/<namespace>/<name> and returns
the distinct parts. In some cases the partition and namespace may be elided and this function
will return the empty string for them then.
If two parts are present, it is assumed they are namespace/name and not partition/name.