Global: Move some WebGPU modules from core to addons.

[Mugen87]

Fixed #29505.

Description

As suggested in #29505 this PR moves some WebGPU modules from core to addons.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	687.46 170.22	687.46 170.22	-3 B -1 B
WebGPU	805.13 216.73	805.13 216.74	-3 B +3 B
WebGPU Nodes	804.64 216.6	804.63 216.59	-3 B -3 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	463.24 111.86	463.24 111.86	-3 B -1 B
WebGPU	534.87 144.3	534.85 144.34	-17 B +35 B
WebGPU Nodes	491.21 134.05	491.2 134.09	-17 B +31 B

[Mugen87]

webgpu_backdrop_water seems to have some timing issues. When updating related code, the example tends to fail although nothing changes at the visuals. Adding it to the exception list for now.

[mrdoob]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	687.46 170.22	687.46 170.22	-3 B -1 B
WebGPU	805.13 216.73	805.13 216.74	-3 B +3 B
WebGPU Nodes	804.64 216.6	804.63 216.59	-3 B -3 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	463.24 111.86	463.24 111.86	-3 B -1 B
WebGPU	534.87 144.3	534.85 144.34	-17 B +35 B
WebGPU Nodes	491.21 134.05	491.2 134.09	-17 B +31 B

I wonder why file sizes didn't get smaller... 🤔