Extend setting base transform to withTransforms param

[nixondesigndev]

Description

This is a request to add support for specifying a base transform (#5853 (comment)) when eager loading asset transforms with withTransforms.

Eager loading image transforms has significantly reduced our db queries (big thanks for that). We're now experimenting adding support for webp using the picture tag but can foresee issues with the implementation of #6381 as I'd assume Craft will need to do a whole new set of queries to do the overrides.

Perhaps eager loading could be enabled with a withTransformOverrides param or withTransforms takes an object of variants.

.withTransforms([{width: 300, height: 300}, {sizes: ['1.5x', '2x', '3x'], format: ['webp']})

[brandonkelly]

That $transformOverrideParameters argument was removed in c4696c6, so just updated your issue.