Parametrize the position of the "back to previous step" link/button

[sergei-maertens]

Taiga DH 685, business case "ondernemers"

DH wishes to move the "back" link from the button row below the form fields to between the step title and "step x from total" text.

Tasks

• [ ] Support icon in back link, possible route is SVG background image. Alternative was offert by Robbert NL DS -> check with him & Sergei what the status is
• [ ] Via theme/styling/design tokens: refactor the page structure (CSS grid?) so that we can arrange the order/position of UI elements through design tokens. Existing/other instances should keep the current layout.

[sergei-maertens]

Refinement: careful, harder than it looks like