Fix handling of skinned meshes for nodes

Second try after the revert in 8a28339 due to an unexpected regression.

- Rigidly animated models (e.g. the glTF frog node) were not working correctly,
  since cloning the mesh ignored the transformation matrices.
  Note that scaling the mesh needs to occur *after* transforming the vertices.
- Visual scale did not apply to skinned models,
  as resetting the animation overwrote scaled vertex data with static positions & normals.
  For backwards compatibility, we now apply a 10x scale to static, non-glTF models.

We now do scale static meshes, as the bug that caused meshes not to be scaled was limited to skeletally animated meshes,
hence we ought not to reproduce it for skinned meshes that do not take advantage of skeletal animations (e.g. current MTG doors).

However, glTF models (e.g. Wuzzy's eyeballs) up until recently were always affected due to technical reasons
(using skeletal animation for rigid animation).

Thus, to preserve behavior, we:

1. Do not apply 10x scale to glTF models.
2. Apply 10x scale to obj models.
3. Apply 10x scale to static x or b3d models, but not to animated ones.

See also: #16141

doc/lua_api.md

@@ -10172,9 +10172,12 @@ Used by `core.register_node`.
     mesh = "",
     -- File name of mesh when using "mesh" drawtype
     -- The center of the node is the model origin.
-    -- For legacy reasons, models in OBJ format use a scale of 1 node = 1 unit;
-    -- all other model file formats use a scale of 1 node = 10 units,
-    -- consistent with the scale used for entities.
+    -- For legacy reasons, this uses a different scale depending on the mesh:
+    -- 1. For glTF models: 10 units = 1 node (consistent with the scale for entities).
+    -- 2. For obj models: 1 unit = 1 node.
+    -- 3. For b3d and x models: 1 unit = 1 node if static, otherwise 10 units = 1 node.
+    -- Using static glTF or obj models is recommended.
+    -- You can use the `visual_scale` multiplier to achieve the expected scale.
 
     selection_box = {
         -- see [Node boxes] for possibilities