New updated header design

[hannefinnoy]

Update to new header design for Altinn studio. The design uses design token colors and text styles from the design system.

It also includes a new design of the menu which also includes app settings now.

Link to design in Figma: https://www.figma.com/file/VAvGOqkMhKM8HL8h4xBeDH7b/Re-design-Altinn-Studio?type=design&node-id=7187%3A50731&mode=design&t=6ClOYi7pyUAijDwP-1

🚧WIP design! ask UX for final design

### Tasks
- [ ] https://github.com/Altinn/altinn-studio/issues/11151
- [ ] https://github.com/Altinn/altinn-studio/issues/11152
- [ ] https://github.com/Altinn/altinn-studio/issues/11153
- [ ] https://github.com/Altinn/altinn-studio/issues/11154