fdo#85876: sw: fix attributes when splitting paragraph

fdo#74981: sw: fix input field handling when splitting paragraphs

The SwInputFld is copied because it doesn't have HasDummyChar() set
although it has 2 dummy characters; TODO why is that...

Change-Id: Iee91c1d0cf7a7a928e7383c1839f8192e8d4d5b0
(cherry picked from commit a1718045bd6218e07caebda7c4cacdcb853eabd3)

fdo#85876: Revert "fdo#74981: cutting nothing should do nothing, ...

... should fix field dupes"

This reverts commit f384598d8eec91c3c0f84a07ff3e59b8e3e13b3f.

The attributes have to be copied in case splitting a paragraph creates
an empty paragraph.

Change-Id: Icd5730dd9ab8a68f737492645988a4d2f07af7a0
(cherry picked from commit 0f78ae1ca33f83737553ad204c869a63498b7d2d)
Reviewed-on: https://gerrit.libreoffice.org/13486
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>