AllocationFilterParser: Add 'nilable' to controller/controllerKind props

Signed-off-by: Bianca Burtoiu <bianca@kubecost.com>

core/pkg/filter/allocation/parser.go

@@ -8,8 +8,8 @@ var allocationFilterFields []*ast.Field = []*ast.Field{
 	ast.NewField(FieldClusterID),
 	ast.NewField(FieldNode),
 	ast.NewField(FieldNamespace),
-	ast.NewField(FieldControllerName),
-	ast.NewField(FieldControllerKind),
+	ast.NewField(FieldControllerName, ast.FieldAttributeNilable),
+	ast.NewField(FieldControllerKind, ast.FieldAttributeNilable),
 	ast.NewField(FieldContainer),
 	ast.NewField(FieldPod),
 	ast.NewField(FieldProvider),