MDL-42403 course: Show bluk move to category only when something selected
MDL-42403 course: Added behat to check visibility of bluk move action
MDL-42403 courses: removed unneeded category check

On course view manage page, JS was not getting initalised as category-listing
is not visible, initialiseCourses is doing unnessary check for category as
it takes care of empty category so it should not return on empty category