tdf#131253 sw: draw frame text boundary on when show formatting marks

tdf#131253 sw: draw frame text boundary on when show formatting marks

It is infuriating to see a border around your image
when there is no border defined. View - Text boundaries
does NOT sound like something that would apply to images,
and it is NOT nice to turn that off because then you also
lose the body text markers as well as the header/footer indicators.

Instead, do the same thing as the page boundaries - only show
the (full) boundary when show formatting marks is turned on
(and there are no partial boundaries for frames...)

I tried to write a GDIMetaFile unit test,
but the dumps were identical - failing to capture this screen artifact.

Change-Id: I7954effc46d977e1761cba71758f7a7af2072807
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/165294
Reviewed-by: Justin Luth <jluth@mail.com>
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>