Text inside block SDTs was shown as Text Fields wich ignored properties such as
alias and formatting. Now those texts are imported as content controls like in
the case of run SDTs.
Added the ability for content controls to remember and export the "multiline"
property of block SDT text.
Some existing tests have been changed due to some different export results.
Change-Id: Ice1eb4ca6dd53c99d5abb239371f8ac896c3b6e4
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/156867
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins
