Nodes: fix atan2

[miko3k]

Description

I noticed that atan2 doesn't work in WebGL, I am getting following error:

FRAGMENT
ERROR: 0:1199: 'atan2' : no matching overloaded function found

Example:

import { AttributeNode, ShaderNode, nodeObject, atan2, MeshStandardNodeMaterial } from "three/examples/jsm/nodes/Nodes";

export const SomeShaderNode = new ShaderNode( ( {uv} ) => {
    return atan2(uv.x, uv.y)
} );

const material = new MeshStandardNodeMaterial();
material.colorNode = SomeShaderNode.call({uv: new AttributeNode('uv')})

This is an attempt to correct this error.

[sunag]

I think we can follow a style similar to WebGPUNodeBuilder?

const glslMethods = {
	atan2: 'atan'
};

...

getMethod( method ) {

	return glslMethods[ method ] || method;

}

[miko3k]

Thanks for feedback. I updated the PR.

[sunag]

Thanks for the contribution!