Render issue with horizontal gutters

[psybers]

All of the sample labels are Avery brand, where there are no horizontal gutters (each label touches the one above/below it). So it was not obvious that there is a rendering bug.

What happens is if you set a horizontal gutter, it will allocate space above the first label. Thus, it artificially inflates the top margin.

For example, this was the settings I used for these labels (https://www.amazon.com/dp/B014IPO0US):

    "royalgreen1660": LabelInfo(
        labels_horizontal=7,
        labels_vertical=22,
        label_size=(25.4 * mm, 9.52 * mm),
        gutter_size=(2.5 * mm, 2.5 * mm),
        margin=(11.55 * mm, (8.73 - 2.5) * mm),
        pagesize=LETTER,
    ),

Note that I had to do 8.73 - 2.5 (subtract out the horizontal gutter height) to get it right.

[jcgruenhage]

A PR for this would be highly appreciated!

[psybers]

I have it fixed in my fork, but there are a lot of other changes in there and I don't have time to slice them out to a PR. Here is the relevant parts:

https://github.com/psybers/paperless-asn-qr-codes/blob/3dc436816512ba755af00d23236c864a5d638213/paperless_asn_qr_codes/avery_labels.py#L115
https://github.com/psybers/paperless-asn-qr-codes/blob/3dc436816512ba755af00d23236c864a5d638213/paperless_asn_qr_codes/avery_labels.py#L117
https://github.com/psybers/paperless-asn-qr-codes/blob/3dc436816512ba755af00d23236c864a5d638213/paperless_asn_qr_codes/avery_labels.py#L144