Implement ChromaticAberrationEffect

[vanruesc]

Description

Implement a ChromaticAberrationEffect.

Tasks

• Create ChromaticAberrationEffect.
• Create chromatic-aberration demo.
• Add unit test.

Implementation Details

• The implementation from v6 can be copied mostly as-is.
• The effect should define an offset input uniform.
  • Also provide an offset setter for this uniform's value.
  • The GlitchEffect provides an offset output uniform.