feat: Allow additional images in Materials

[eonarheim]

===:clipboard: PR Checklist :clipboard:===

• 📌 issue exists in github for these changes
• 🔬 existing tests still pass
• 🙈 code conforms to the style guide
• 📐 new tests written and passing / old tests updated with new scenario(s)
• 📄 changelog entry added (or not needed)

==================

This PR adds the ability to load additional images into ex.Materials!

const noise = new ex.ImageSource('./noise.avif');
loader.addResource(noise);

var waterMaterial = game.graphicsContext.createMaterial({
  name: 'water',
  fragmentSource: waterFrag,
  color: ex.Color.fromRGB(55, 0, 200, .6),
  images: {
    u_noise: noise
  }
});