Vue: More Tests

[felixgabler]

Let us collect files which need testing in this issue. We can then write tests as soon as we find time and cross them off.

[felixgabler]

• [ ] modules/notifications (browserNotif on/off, body empty, etc)
• [ ] modules/reformat/formats (every format should be tested thoroughly)
• [ ] util/validation.ts

[felixgabler]

We also need to run the tests in CI