[3d] better solution to support reading extra resource/texture

[jtydhr88]

just find out a correct way to handle extra resource/texture reading for 3d model, rather than writting an override class.
Tested on:
OBJ+MTL

GLTF+Extra Texture

FBX+Extra Texture

Resolved #4101

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[webfiltered]

Good to go w/nits!

[jtydhr88]

After a period of testing, I found that in order to better implement this texture modification, we still need to support uploading models and their corresponding resources to different folders. Previously, all model files would be uploaded to the '3d' folder, and during the upload process, files with duplicate names would be automatically renamed. As for resource files, they needed to be manually copied to the 3d folder, which created a problem where files with the same names would be overwritten. Therefore, a better approach is to allow users to upload different models and their corresponding resources to different subfolders. This is the change implemented in this PR.
Demo is

2025-06-20.04-56-34.mp4

need BE change comfyanonymous/ComfyUI#8597