libview: Allow adding freetext annots

Also draws a rectangle in the region being dragged.
Shell: Add support for adding free text annots
libdocument: Add font property to freetext annots
pdf: Save font of freetext annotations
shell: Add font property of freetext annotations
libdocument:Add quadding property of freetextannot
pdf: Save quadding of free text annotations
shell: Add quadding property of freetext annots
libdocument: Add EvAnnotationCalloutLine
libview: (WIP) tooltip issue freetext annots
libdocument:Add intent property of freetext annots