Clarify intrinsic/local Euler rotation order in 3D documentation

[aaronfranke]

This PR fixes #105115 by clarifying the intrinsic/local Euler rotation behavior.

Rotating around the object's local axes is called the "intrinsic" rotation in math-speak. While the documentation already mentioned "local" in a few places, we didn't mention "intrinsic" even once before, and didn't mention "local" enough either.

Game developers expect intrinsic rotation, but Blender uses extrinsic. Either way, it's good clarify to avoid confusion.

[Mickeon]

This PR is more extensive and thorough than #106261

In Godot, Euler angles always use intrinsic order. as a note right in the middle of a line is a bit odd.

This is noteworthy information, sure, but a majority of users do not know what "intrinsic" means, so this ends up breaking the flow and making it sound more complicated than it is. It doesn't help that the only place in this PR that explains what "intrinsic" roughly means is, unusually, deeply nested in the (very advanced) Quaternion constructor as a huge, inline remark.

"intrinsic" vs. "extrinsic" could be something worth explaining across the whole EulerOrder enum if #98233 were merged

[fire]

It seems like if the developer wants to lookup what Godot Engine EULER_ORDER_XYZ means in Blender it might help to put it in the tooltip.

[TokageItLab]

@Mickeon Can you re-review this PR?

[lyuma]

docs change looks good (reviewed with fire and aaronfranke)

[Repiteo]

Thanks!