Responsive design of columns in "lage"

[hannefinnoy]

When the user increases or decreases their screen reader window the user interface of the "lage" page should adapt to fit it so that it is still possible to create an app without too much hassle.

### Tasks
- [ ] Design different views of the "lage" page for different screen sizes
- [ ] Decide if we are going to offer different templates in first version, or develope responsive design
- [ ] https://github.com/Altinn/altinn-studio/issues/12787