Standardize order of OK, Cancel, Help buttons in all dialog windows
Protect sheet dialog

Change-Id: I4549d999a4bb73102eb8ab6b443143956923ae3e
Reviewed-on: https://gerrit.libreoffice.org/22254Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Olivier Hallot <ohallot@collabora.co.uk>
Tested-by: Olivier Hallot <ohallot@collabora.co.uk>