StorageTexture: Add width and height getters

[gkjohnson]

Related issue: --

Description

Adds "width" and "height" convenience getters for Storage texture to map Texture and RenderTarget.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.37 78.9	338.37 78.9	+0 B +0 B
WebGPU	561.4 155.29	561.48 155.31	+74 B +20 B
WebGPU Nodes	560.01 155.05	560.09 155.07	+74 B +18 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	469.75 113.6	469.75 113.6	+0 B +0 B
WebGPU	636.14 172.14	636.14 172.14	+0 B +0 B
WebGPU Nodes	590.79 161.38	590.79 161.38	+0 B +0 B

[sunag]

It wouldn't be redundant with #31025?

[gkjohnson]

You're right! I missed that it was already supported, I guess.