feat: Add group by button to equipment page

Closes #7636
Closes #7651

This commit creates a new button on the equipment page that allows the user to group their equipment type (body location) instead of simply by class.

website/client/js/controllers/sortableInventoryCtrl.js

@@ -15,6 +15,10 @@ habitrpg.controller('SortableInventoryController', ['$scope',
       }
     };
 
+    $scope.setGrouping = function (grouping) {
+      $scope.groupingChoice = grouping;
+    };
+    
     $scope.orderChoice = 'set';
     $scope.setOrder($scope.orderChoice);
 }]);