Support for X3D 4.0 audio nodes

[brutzman]

x3dtovrml.exe validation needs to support new X3D 4.0 audio nodes

• X3D Architecture 4.0, clause 16 Sound component
• https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-IS.proof/Part01/components/sound.html

Example:

• https://www.web3d.org/x3d/content/examples/X3dForAdvancedModeling/AudioSpatialSound/AllAudioGraphNodesTestIndex.html
  C:\x3d-code\www.web3d.org\x3d\content\examples\X3dForAdvancedModeling/AudioSpatialSound//AllAudioGraphNodesTest.x3d processing with X3dToX3dvClassicVrmlEncoding stylesheet ClassicVRML validation: tovrmlx3d.exe AudioSpatialSound//AllAudioGraphNodesTest.x3dv --validate --enable-downloads tovrmlx3d: Warning: VRML/X3D: Error when reading, will skip the rest of X3D file: Error at line 33 column 23: Invalid X3D node content (probably unknown or not allowed field, prototype or VRML 1.0-style children) inside "Appearance": got "AcousticProperties"