ISTWCMS-5593: code cleanup

src/patterns/01-core/mixins/_uw-mixins.scss

src/patterns/03-layouts/layout/_layout-base.scss

src/patterns/03-layouts/layout/_layout.scss

...terns/03-layouts/layout/layout--2-col/_layout--2-col.scss

...terns/03-layouts/layout/layout--3-col/_layout--3-col.scss

...terns/03-layouts/layout/layout--4-col/_layout--4-col.scss

...terns/03-layouts/layout/layout--5-col/_layout--5-col.scss

...out/layout--inverted-l-left/_layout--inverted-l-left.scss

...t/layout--inverted-l-right/_layout--inverted-l-right.scss