Set $wgBabelCategoryNames for betawikiversity

This change sets the $wgBabelCategoryNames configuration variable for
Beta Wikiversity per community consensus at
https://beta.wikiversity.org/w/index.php?oldid=154519#List_of_active_users_for_a_specific_language

Bug: 64168
Change-Id: I72b9d57b4297c3a0f3d187bb9651ab63be47c1c8