initial commit for fdc3 handlers refactor

@sebbenmbarek @robmoffat this should now be ready for review.

broke out the FDC3 handlers
separated out into a '1.2' directory
consolidated the preload structure for the fdc3 api injection into views
much cleanup

There will be more iteration on top of this refactor (for example, I want to simplify/reduce the # of different preloads generated), but think it would be better to merge this first - as this is already a huge PR. Hopefully, can be much more incremental from here on out.

finos / FDC3-Sail

initial commit for fdc3 handlers refactor #65