LWOLoader: Deprecate loader.

[Mugen87]

Related issue: -

Description

I'd like to propose to deprecate LWOLoader:

• It's a proprietary format intended for the LightWave ecosystem.
• Blender stopped built-in LWO support since 3.xx and none of the other major DCC tools (Maya, 3DS Max, Cinema 4D, Houdini) import LWO out of the box.
• Modern asset/scan pipelines (Sketchfab, Polycam, RealityCapture, KIRI Engine, Substance, USD-based tooling) provide no LWO export.
• None of the big game engines (at least Unreal, Unity, CryEngine, Godot) import LWO out of the box.
• LightWave supports FBX and glTF export so we can guide users to other formats three.js supports.
• Also considering the maintenance costs: The loader with its parse modules have ~3,000 LOC. Two parallel format versions (LWO2 and LWO3) must be kept working. Regarding the code, almost FBXLoader's footprint but LWO is far less relevant.

@mrdoob Similar to #33363, I'd like your approval on this one 😇 . Is this change okay with you?