Rationale
All mixins in 'mediawiki.mixins.less' besides screen reader helper mixin .mixin-screen-reader-text() are aiming to overcome cross browser issues and provide a shorthand for normalizing rendering across the board.
They all use names following CSS properties.
After @embed was removed from .background-image() in 792ba93 the mixin is just sparing 4 chars now and providing less added value in IDEs with property autocomplete in comparison to CSS property, making this mixins technical debt in our codebases.
Criteria for Done
- Deprecate .background-image() CodeSearch/.list-style-image() in MW 1.38
- Remove following minor release 1.39