Consider falling back to webp based on filesize

Problem/Motivation

From @catch

would we want to consider some kind of configurable filesize threshold where below a certain point we always skip AVIF and use webp instead? Have seen various discussions that decoding AVIF in the browser is a lot more expensive than webp, which can undo the bandwidth savings with smaller images.

Steps to reproduce

NA

Proposed resolution

TBD

Remaining tasks

Determine if there should be a fallback
If yes do it

User interface changes

NA

Introduced terminology

NA

API changes

NA

Data model changes

NA

Release notes snippet

NA