fdo#78062: Broadcast only on non-empty cells within deleted range.

We don't want to broadcast over the whole selected range, which may be
the whole sheet which is well over 1 billion cells !

(cherry picked from commit af7df25bcc8bc95462e2b3bf8c003d035111a479)

Conflicts:
	sc/source/ui/inc/undobase.hxx
	sc/source/ui/undo/undobase.cxx

Change-Id: I7c139ce5efe09312cf824e35f0efe551184032eb
Reviewed-on: https://gerrit.libreoffice.org/9240
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>