Add support for AVIF format

AVIF image format support is almost ready for Drupal 11, just like WebP in Drupal core, through image effect “convert” in Let GDToolkit support AVIF image format → .

Actually, WebP quality can't be set globally, the same with AVIF. So this could be even better than the proposed global quality config for WebP in Allow WebP quality to be configurable in GD2 image manipulation toolkit settings ✨ Allow WebP quality to be configurable in GD2 image manipulation toolkit settings Needs review .