New annotation method to annotate PDF documents

First attempt to unify working with annotations, and hopefully remove the toolbar for annotations. There are some issues where this has been discussed one way or the other, I need to search them.

@nbenitez What do you think?

I have the idea that this may work better on top of !55.

The widget is as follows:

I am not happy with the radio menu, nor with the icons. But it helps to get the idea.