Use avif with webp fallback for all core image styles

Problem/Motivation

#3510582: AVIF conversion with WEBP fallback added an AVIF image effect with configurable fallback.

Core already ships with webp, but we can change this to AVIF with a webp fallback to have smaller image derivatives out of the box.

This should be done for both the standard profile and Umami - can be one MR for all shipped image styles.

I'll open an equivalent issue for Drupal CMS too.

Steps to reproduce

Proposed resolution

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User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet