clean up on the semantic builder
registries are now an observable type
Mapping single items to the collection equavilant

wip gh-20
some fixes to pass unit tests

gh-20
moving the guarding logic to srp observers

was working on gh-20. Ran into issues which requires gh-15 to be solved
first before moving on.
Weighting upon the registrations of the PipeOutputPackage instances

This solves the ticket gh-15