Test support for multiple nodes / collections defined via URI #fragment

[Mikxox]

It is unclear how the code will / should behave when dereferencing a page with multiple nodes / collections identified via #fragment.
For a collection, only the first found collection will be used and others ignored but nodes & shape will get improperly linked.
For multiple nodes it is unclear how the code should behave. Currently all members will be 'linked' to each node since members are defined on the collection not a node. Relation linking depends on the parsing done by the metadata extractor.