Fix typescript issues

[nickspaargaren]

What

• Fix TypeScript issues
• Updates @sentry/react to v8
• Updates connected-react-router to v6

How to test

1. Run git checkout develop.
2. Follow the build instructions to run the project.
3. Run npx yarn tsc --noEmit
4. Verify that there are currently two TypeScript errors (Sentry and ConnectedRouter).
5. Checkout this branch / this PR.
6. Run yarn install and optionally follow the build instructions again to run the project.
7. Run npx yarn tsc --noEmit again.
8. Verify that the TypeScript errors are gone.
9. Make sure the project runs as expected.

Notes

I followed the official migration guides:

• https://github.com/supasate/connected-react-router/blob/master/FAQ.md#how-to-migrate-from-v4-to-v5v6
• https://docs.sentry.io/platforms/javascript/guides/react/migration/

Closes #278

[nickspaargaren]

@thanasis457, do you still want to take a look at this? #278