security.ui: hide login/out buttons for RAP
utility.singlesource.rap: add rap implementation for authentication
databrowser2: add "secure_data_browser" preference to require
authentication to open data browser
BOY: use file icon for open top opi items. open data browser in the same
window for RAP.
Merge branch '3.2.x' of https://github.com/ControlSystemStudio/cs-studio.git into 3.2.x