Implement LensDistortionEffect

[vanruesc]

Description

Implement a LensDistortionEffect.

Tasks

• Create LensDistortionEffect.
• Create lens-distortion demo.
• Add unit test.

Implementation Details

• The implementation from v6 can be copied mostly as-is.

[seralichtenhahn]

@vanruesc I can work on this!

[vanruesc]

Ok, thanks!

[seralichtenhahn]

Thanks @vanruesc 🙏

I opened a PR with the implementation (#627). I'd love to hear your thoughts.

[vanruesc]

Nice, I'll take a look when I get a chance.