Implement ShockWaveEffect

[vanruesc]

Description

Implement a ShockWaveEffect.

References:

• https://github.com/pmndrs/postprocessing/blob/e053ac37ed095fafa31d3bb377e37ffa7810f12b/src/effects/ShockWaveEffect.js
• https://www.shadertoy.com/view/ddBfzm

Tasks

• Create ShockWaveEffect.
• Create shock-wave demo.
• Add unit test.

Implementation Details

• The spherical shock wave should be depth-aware.
• Support multiple simultaneous shock waves.
  • The maximum number of shock waves should be configurable.