MDL-47146 grades: fix class names

Class names for grade categories were the same as for the columns in the table causing errors
when selecting All/None items
MDL-47146 grades: merge simple and full view in setup

AMOS BEGIN
 CPY [categoriesanditems,core_grades],[setup,core_grades]
AMOS END
MDL-47146 grades: remove advanced mode in setup
MDL-47146 grades: fix navigation bar in grades setup pages

Part of: MDL-46576
MDL-47146 grades: change action buttons on setup screen

Part of: MDL-46576
MDL-47146 grades: change columns on setup page

Part of: MDL-46576
MDL-47146 grades: merge weight and extra credit columns in setup
make range column read-only always
MDL-47146 grades: Removed unused setup columns