**Godot version:** Master (3cfb67e0f) **OS/device including version:** Any **Issue description:** As discussed a few times on IRC, and exemplified by many bug reports, our current fixed size for the Message Queue is problematic. It currently defaults to `1024` (see `memory/limits/message_queue/max_size_kb`), and many users need to increase it to prevent overflow when handling a large amount of messages (which can happen easily in the editor when using e.g. large TileSets #29238 or Skeletons #35652). As discussed with @reduz, Message Queue should be changed to use a page allocator so that its size can grow as needed, preventing overflows. Situations which can cause a Message Queue overflow like #29238 or #35652 should however be fixed in the Inspector itself, as even increasing the MQ will just make things functional again, but it will still freeze a long time while populating all those controls. --- Example output to help uses find this issue: ``` Object was deleted while awaiting a callback Object was deleted while awaiting a callback Object was deleted while awaiting a callback Object was deleted while awaiting a callback Object was deleted while awaiting a callback Object was deleted while awaiting a callback Object was deleted while awaiting a callback Object was deleted while awaiting a callback TOTAL BYTES: 1048560 NULL count: 8 CALL : 3 CALL _update_callback: 37181 CALL _update_minimum_size: 5 CALL _sort_children: 6479 CALL _emit_change: 1 CALL _update_script_names: 1 CALL _update_script_connections: 1 CALL _test_update_tree: 9 CALL _node_selected: 1 CALL _update_bone_list: 1 ERROR: push_call: Message queue out of memory. Try increasing 'message_queue_size_kb' in project settings. At: core/message_queue.cpp:55. Failed method: VBoxContainer:_update_callback target ID: 74982 ```