Optimize Onboarding Flow on macOS

[casaout]

• [x] On Startup, check if trackers are enabled and permission there, if not, show onboarding page again
• [ ] #313
• [ ] when permissions are removed and onboarding window is opened again:
  • [ ] jump to permissions-page (not study-info page) in onboarding page
  • [ ] when permissions are missing also reset the flag so third/confirmation-page on onboarding-page is shown again
• [ ] #301
• [ ] log given permissions and removed permissions in the usagelog and log files
• [ ] add #332