feat: Support image filtering modes on ImageSource & Raster Graphics

[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)

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Related to the roadmap for v0.26.0 #1161, this PR exposes different webgl texture blending modes to the user. I've attempted to give them names that are indicative of their function.

• ex.ImageFiltering.Blended - Blended is useful when you have high resolution artwork and would like it blended and smoothed
• ex.ImageFiltering.Pixel - Pixel is useful when you do not want smoothing aka antialiasing applied to your graphics.

After the v0.25.0 and the switch to webgl, Excalibur really only catered to pixel art styles, now supports hi-res art styles as well!

Changes:

• Excalibur will set a "default" blend mode based on the ex.EngineOption antialiasing property, but can be overridden per graphic
  • antialiasing: true, then the blend mode defaults to ex.ImageFiltering.Blended
  • antialiasing: false, then the blend mode defaults to ex.ImageFiltering.Pixel
• ex.Text/ex.Font defaults to blended which improves the default look of text rendering dramatically!
• ex.Circle and ex.Polygon also default to blended which improves the default look dramatically!
• ex.ImageSource can now specify a blend mode before the Image is loaded, otherwise