DispatchingEntityIdParser finds the correct type of EntityId to construct by matchign a given ID serialization against regular expressions managed by EntityTypeDefinitions. Those patterns match "Q1234" for items, "P1234" for properties, etc.

To support foreign IDs, this mechanism needs to be adapted so it can handle IDs of the form "foo:Q11234" and "a:b:c:P23768", and still determine the correct entity type.