🚀 [Feature] Frontend: Optimize Menu

[Bettelstab]

Note: Sorry, I should have made separate issues for the different parts. Some got bigger than I thought. Now it's a bit hard to follow. :/

🚀 Feature

• Check contours in dark mode (fix(frontend): header design fixes and adaptions for first release #1249)
• UserInfo padding / margin (fix(frontend): header design fixes and adaptions for first release #1249)
• UserInfo menu as in template (feat(frontend): userinfo dropdown style #1267)
• Deactivate Mall in TabControl (feat(frontend): functional tabcontrol #1193)
• Functional links in TabControl (feat(frontend): functional tabcontrol #1193)
• Replace message icon with (non-scrolling) logo (fix(frontend): header design fixes and adaptions for first release #1249)
• Mobile Create button fully visible when open (fix(frontend): createbuttonmobile fix #1194)

Open questions for designer

• Design for mobile UserDropdown?
• Can we use generic drawers instead? (No)
• Icon for admin link (included in 🚀 [Feature] Design: Refinements #1307 )