sw: fix pasting multiple flys in SwFEShell::Paste()
This was most recently fixed in
3cfd63cb55ab1a7e6df53eaeb2a7623be05983d0
but that didn't take into account that now with Ctrl+A multiple flys can
be selected and copied, and all of them should be pasted; remove the odd
restriction to paste only one text frame.
This reveals that pasting a text frame will actually select the text
frame, so subsequent flys end up anchored inside the text frame; delay
selection until all flys have been pasted.
Change-Id: I049f60ca9656e5075d481d4501bb1ffdd28a4e21
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/135366
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>