Redirect to mete to add barcode on click

[fupduck]

Add the option to click on the warning that the barcode is not known, so that we can directly add it in mete.

To achieve this I added the url prop to Mete.vue.

NOTE: I had to cast this.$root to any - if you have better ideas please share!

I assume this is quite hacky - nicer approaches welcome.

And help wanted to fix the checks 🙃

To test this add this.addFromBarcode('asdf?!<'); to Register.vue's mounted function.

[m0ppers]

great! always wantend this ❤️ . I think the non hacky solution would be to emit an event from the register and then connect to that in App. but I like to have this feature ASAP 😂