Shaders: Add support for texture2d parameters #254

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Description

Implement support for 2d textures, for both files (images) and the spout/sink system to bring in source data. This functionality will allow a massive increase in possible shaders, enabling effects such as SMAA, 3D scenes, particles, and more.

Parent Issue: #5

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Checklist

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• I am willing to pay someone to implement this feature.
• This feature absolutely can't be done with already existing features.