Convert focal point selector tool into a standalone form element

@ankitv18 did you already had some time to tackle #33 ?

Hiding patches because there is a recent Merge Request for this ticket.

Still the problem for [site]/media/add/image is not resolved #33

unassigning this, because there is no response (yet). and others already worked on it.

Tried to debug the latest version and get it working on [site]/media/add/image, but there is still a lot to do.