ISTWCMS-5905: adding background-image and updating layouts to use it

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

...tterns/03-layouts/layout/layout--1-col/layout--1-col.twig

...tterns/03-layouts/layout/layout--2-col/layout--2-col.twig

...tterns/03-layouts/layout/layout--3-col/layout--3-col.twig

...tterns/03-layouts/layout/layout--4-col/layout--4-col.twig

...tterns/03-layouts/layout/layout--5-col/layout--5-col.twig

...yout/layout--inverted-l-left/layout--inverted-l-left.twig

...ut/layout--inverted-l-right/layout--inverted-l-right.twig

src/patterns/04-components/_index.scss

...rns/04-components/background-image/_background-image.scss

...erns/04-components/background-image/background-image.twig