Move helpers to convert between the Rectangle, Point and Size
classes in vcl and in css::awt from VCLUnoHelper (in the toolkit module)
to vcl::unohelper (in the vcl module), for reuse in vcl in upcoming
commits.
Change-Id: I7b11c8a6b8c843a01ce25b1e4c0fb1869ad1e6ee
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/177816
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
