menubar swxform: copy of swriter menubar.xml

swxform use the same actions than swriter
to a better maintanance swxform can use swriter
eg. the old menubar didn't had form items available

Change-Id: I6797ba26e3468a116795fdeb8f2acc0e51a48516
Reviewed-on: https://gerrit.libreoffice.org/56066
Tested-by: Jenkins
Reviewed-by: Heiko Tietze <tietze.heiko@gmail.com>