Add support for barcodes

[budda85]

Hey,
I would like to print labels with barcodes. I would like to use the whole thing with grocy. All the forks that are currently available are outdated, are no longer maintained and therefore don't work.
Your project here is, as far as I have seen, the only up to date one. Would it be possible to add barcode support here somehow?
A fork has apparently already extended the old project, but I can't get it to work at the moment.
Grocy has an interface or calls a webhook to print a label.
Würde mich freuen wenn man das irgendwie ans laufen bekommen würde.
I would be happy if I could somehow get this to work.

[FriedrichFroebel]

In theory, barcodes can already be printed through the API by providing a corresponding image file, although this is limited to the Git version for now as long as I did not publish a new release. You can basically use the old project code for generating the image file and just send it to the API, as shown in #14 (comment).

I do not have any direct plans to add barcode support for now, as this probably requires an additional GUI view and there are tons of different options. IMHO the webhook data sent by Grocy is too specific to be implemented by a general purpose tool like brother_ql_web. Nevertheless, I am open to merge a corresponding PR which properly implements such a API as an optional feature, providing sufficient test coverage as well.