* Made the Basis euler orders indexed via enum.
* Node3D has a new rotation_order property to choose Euler rotation order.
* Node3D has also a rotation_mode property to choose between Euler, Quaternion and Basis
Exposing these modes as well as the order makes Godot a lot friendlier for animators, which can choose the best way to interpolate rotations.
The new *Basis* mode makes the (exposed) transform property obsolete, so it was removed (can still be accessed by code of course).
Roughly based on https://github.com/godotengine/godot-proposals/issues/3375 (used format is slightly different).
* Implement bitwidth based animation compression (see animation.h for format).
* Can compress imported animations up to 10 times.
* Compression format opens the door to streaming.
* Works transparently (happens all inside animation.h)
The order of numbers is not changed except for Transform2D. All logic is done inside of their structures (and not in Variant).
For the number of decimals printed, they now use String::num_real which works best with real_t, except for Color which is fixed at 4 decimals (this is a reliable number of float digits when converting from 16-bpc so it seems like a good choice)
