DEPL — ExternalReferneceEndpoint

For ExternalReferneceEndpoint add a navigable association to
Requirement with multiplicity being "*". Rationale for change is to allow
for PSMs to qualify the requirements needed for an
ExternalReferenceEndpoint. An example is a SWRadio use cases for this are:
a. To be able to specify a service needed that the domain is aware of.
b. To be able specify a device that deployment machinery used for the
deployment of a component.
c. To be able to specify a service that was chosen by the deployment
machinery that was specified for a component deployment requirement.