This PR does a few things:

GS1 / Datamatrix (DM) related parts: 
- Adds in ability to print DM barcode (note: still requires additional package installation to work correctly)
- Adds UoM GS1 rules + yard UoM (note: some Odoo UoMs are not supported by GS1 and will not print in GS1 DMs)
- Print product GS1 barcodes in "Package Barcode with Content" report (note: only when product barcode is EAN compliant + prints additional info when applicable in this case)
- Include product UoM in DM in "Package Barcode with Content" report when valid product GS1 (note: number of digits, including precision digits, are limited in GS1 and will not print in GS1 DM if too long) 
- Add option to print GS1 DMs for Lot/SN labels (note: will only include product in GS1 barcode if EAN compliant)
- Print GS1 SSCC DM for packages when package name is a valid SSCC number (note: for reports: Package with Content, Package Barcode (PDF), and Package Barcode (ZPL))

Label improvements related parts:
- Make Lot/SN label PDF reports match ZPL layout and also follow 4x12 format (same as product label 4x12 layout)
- Allow printing "Package Barcode with Content" directly from picking
- Make MRP "Finish Product Labels" (PDF) print in standard 4x12 layout (previously was a non-standard format)
- Fix MRP label (ZPL) so that a valid zpl is always created regardless of barcode/tracking status
- Add new wizard to print a pickings' SN/Lot labels (via existing "Print Label" button)

See individual commits for additional details for each part's implementations.

ENT PR: odoo/enterprise#23323
Upgrade PR: odoo/upgrade#3202

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