Creating an AttachmentPresenter @WIP

This ties into a configurable behavior that I want to explore; Namely
looking up the appropriate presenter for a given work type, predicate,
and value.

This will also help in the ability to reuse views by presenter type.
The attachment presenter is much more complicated than the other
presenters, but that isn't to say there won't be other classes of
presenters that make sense.

@WIP

This is incomplete (hence the @WIP tag). But it captures an idea.
Note that the Value Presenter and the Attachment Presenter are
duplications of code. I am not satisfied with the inheritance scheme
as I believe there are composable ways of doing this.
@WIP
Extracting a value_presenter_finder class
Tidying up ValuePresenterFinder behavior
Adding specs for value presenter finder
Tidying up a missing test case
Tidying up persistence coordinator tests
Merge branch 'working-on-attachment-presenter'

* working-on-attachment-presenter:
  Tidying up persistence coordinator tests
  Tidying up a missing test case
  Adding specs for value presenter finder
  Tidying up ValuePresenterFinder behavior
  Extracting a value_presenter_finder class
  @WIP
  Creating an AttachmentPresenter @WIP