UNO command SID_GETINVOLVED added with access to the website
from all main menus under Help
Dispensable ellipsis removed from other UNO commands around Help

Change-Id: I79536be3de31f55a7b208bcdd5a243e05b3d3668
Reviewed-on: https://gerrit.libreoffice.org/61238
Tested-by: Jenkins
Reviewed-by: Heiko Tietze <tietze.heiko@gmail.com>