Show Phrases instead of Permission Names on "Advanced Permission" screen

Tree section advanced permission screen (User Management -> Groups -> Edit Group -> Permissions -> Change, see attachment) is used to set tree section
advanced permissions. Advanced permission names are understandable for developers, but I doubt, that regular site administrators understands them
(e.g. "in-portal:users_list.advanced:send_email").

Solution:

Show nice phrase instead of permission name. Phrase should consist of "la_permission_" prefix and permission name: "la_permission_<permission_name>". We could leave actual permission name in debug mode (under permission phrase, small font, gray color as in configuration variable lists).