Devtools layout issues in new DS version

[bjosttveit]

Description of the bug

There are several unintended changes to the look and layout of Dev Tools since #3231. Since we don't visually test Dev Tools, its not surprising that this slipped through.

Examples:

1. Tab panel padding should be removed (essentially everywhere tabs are used, main tabs, component details)
   
2. Expressions content not filling the panel
   
3. Scrolling is broken in all tabs, making especially logs, layout, and component tabs unusable. Makes general and expressions tabs annoying.
4. Generate PDF modal does not size the content properly, on my screen you can't see the bottom of the PDF:
   

Steps To Reproduce

Open dev tools

Additional Information

No response