Update doxygen and fix documentation (#5106)

Update Doxyfile to version 1.9.1

Re-enable doxygen CI checker

Fix some regular comments that should have been doc comments

Document void return types for some inline functions explicitly

Move start of some doxygen groups so they are included always, and not left
out of certain ifdefs

Ignore some doxygen warnings:
    Member (function) is not documented in headers
    Documented empty return type in headers
    Argument has multiple @param documentation sections

JerryScript-DCO-1.0-Signed-off-by: Máté Tokodi mate.tokodi@szteszoftver.hu

jerry-core/ecma/builtin-objects/ecma-builtin-helpers-json.c

@@ -55,9 +55,9 @@ ecma_json_has_object_in_stack (ecma_json_occurrence_stack_item_t *stack_p, /**<
   return false;
 } /* ecma_json_has_object_in_stack */
 
-#endif /* JERRY_BUILTIN_JSON */
-
 /**
  * @}
  * @}
  */
+
+#endif /* JERRY_BUILTIN_JSON */

jerry-core/ecma/builtin-objects/ecma-builtin-helpers.h

@@ -261,7 +261,8 @@ ecma_value_t ecma_builtin_helper_error_dispatch_call (jerry_error_t error_type,
 typedef ecma_value_t (*ecma_builtin_helper_sort_compare_fn_t) (ecma_value_t lhs, /**< left value */
                                                                ecma_value_t rhs, /**< right value */
                                                                ecma_value_t compare_func, /**< compare function */
-                                                               ecma_object_t *array_buffer_p); /**< arrayBuffer */
+                                                               ecma_object_t *array_buffer_p /**< arrayBuffer */
+                                                               );
 
 ecma_value_t ecma_builtin_helper_array_merge_sort_helper (ecma_value_t *array_p,
                                                           uint32_t length,