This PR implements:
* A new hint: PROPERTY_HINT_NODE_TYPE for variant type OBJECT, which can take specific node types as hint string.
* The editor will show it as a node path, but will set it as a pointer to a node from the current scene if you select a path.
* When scene is saved, the node path is saved, then restored as a pointer.
NOTE: This is a proof of concept and this approach will most likely not work. The reason if that, if the node referenced is deleted, then when trying to edit this the node will become invalid.
Potential workarounds: Since this uses the Variant API, it should obtain the pointer from the Variant object ID. Yet, this would either only really work in GDScript or it would need to be implemented with workarounds in every language.
Alternative ways to make this work: Nodes could export an additional property with a node path (like for which_node, it could be which_node_path).
Another alternative: Path editing could happen as a hidden metadata (ignoring the pointer).
* Ensures thread safety when resources are destroyed.
* Simplified API by always forcing `ResourceCache::get_ref`, which needs less hacks and is fully thread safe.
* Removed RWLock for resources because its not possible to use for the new logic. Should not be a problem.
Supersedes #57533
* Allows running the game in "movie writer" mode.
* It ensures entirely stable framerate, so your run can be saved stable and with proper sound (which is impossible if your CPU/GPU can't sustain doing this in real-time).
* If disabling vsync, it can save movies faster than the game is run, but if you want to control the interaction it can get difficult.
* Implements a simple, default MJPEG writer.
This new features has two main use cases, which have high demand:
* Saving game videos in high quality and ensuring the frame rate is *completely* stable, always.
* Using Godot as a tool to make movies and animations (which is ideal if you want interaction, or creating them procedurally. No other software is as good for this).
**Note**: This feature **IS NOT** for capturing real-time footage. Use something like OBS, SimpleScreenRecorder or FRAPS to achieve that, as they do a much better job at intercepting the compositor than Godot can probably do using Vulkan or OpenGL natively. If your game runs near real-time when capturing, you can still use this feature but it will play no sound (sound will be saved directly).
Usage:
$ godot --write-movie movie.avi [scene_file.tscn]
Missing:
* Options for configuring video writing via GLOBAL_DEF
* UI Menu for launching with this mode from the editor.
* Add to list of command line options.
* Add a feature tag to override configurations when movie writing (fantastic for saving videos with highest quality settings).
Clean up and do fixes to hash functions and newly introduced murmur3 hashes in #61934
* Clean up usage of murmur3
* Fixed usages of binary murmur3 on floats (this is invalid)
* Changed DJB2 to use xor (which seems to be better)
This is done to prevent reducing texture quality when it doesn't save
much video memory, especially for pixel art.
The size threshold can be adjusted in the project settings.
To get the previous behavior where textures detected to be used in 3D
had their compression mode always set to VRAM, set this to the lowest value
(16).
