WebGPURenderer: update sampler bindings on texture change

[aardgoose]

Replacing the matcap texture by dragging a new matcap png in recent MeshMatcapNode Material exposes a bug where when a texture is changed, the related sampler binding is not, resulting in a failure in createBindGroup().

Update the sampler texture in these cases, we don't need to flag the update because the related sampledTexture binding will flag the update as required. The WebGL backend does not have this problem.

[RenaudRohlinger]

In some rare case I've experienced unsync of Sampler, as I dug deeper I also found issue with NodeSampled when resizing the screen with a node using a RenderTarget like so:

this._fbo = new RenderTarget();
const sampler = texture(this._fbo.texture);

I get this error (on screen resize):

Which will then generator an error in WebGPUBindingUtils.createBindGroup --> textureData.texture is not defined:

// `textureData.texture` is not defined because `textureData` is equal to `{}`
resourceGPU = textureData.texture.createView( { aspect: aspectGPU, dimension: dimensionViewGPU, mipLevelCount: binding.store ? 1 : textureData.mipLevelCount } );

I suspect it's due to the call of renderTarget.setSize() triggering a dispose event, which destroys the current textures attached to the renderTarget. Then, the textureGPU is re-bound too late to textureData.texture, possibly on the subsequent frame or even never?

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Edit: My issue was only on Sampled node Sampler, the similarity of the names confused me, everything is alright regarding this PR!

/cc @aardgoose @sunag