fdo#78054: Initialize drawing layer when the document contains notes.

Don't be fooled even when the document doesn't have a drawing layer
initialized.  Sometimes a note creates caption on demand later, but if
the drawing layer isn't there the caption will not get created, which
ultimately causes this crash.

(cherry picked from commit fe451fb94a33c914c0a7c1265c013d9704af850a)

Conflicts:
	sc/inc/document.hxx

Change-Id: I37f4902fa84de91c9f793dc352127d9345a725e3
Reviewed-on: https://gerrit.libreoffice.org/9254
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>