Magnets are expressed in two different ways: a hash and a link. Both
of these mean the same thing with a magnet link giving more information
if required.
However, there was a disconnect if a hash was present or a link was
present and required many steps to check which was available. Unify
magnets by creating a parent structure that attempts to extract
the hash or create a link in the event that either parameter isn't
provided.
Replace everything except bookmarks (to prevent CoreData complaints
and unnecessary abstraction) to use the new Magnet system.
Signed-off-by: kingbri <bdashore3@proton.me>