Add a ZPL Conversion Function

[william-davis-dev]

Description

This PR adds a function to convert ZPL (Zebra Programming Language) into images.

Unfortunately, there are no offline NodeJS libraries which support the full spec of the ZPL language. Thus, this function uses the Labelary APIs which are freely available (with rate limits).

Since this function uses an external API call, auto-bake is disabled by default. The Labelary URL which is used is also available as an editable option (although using any other URL is unlikely to be successful).

Testing

For testing, I used the sample ZPL segment from the Labelary online viewer:

^XA

^FX Top section with logo, name and address.
^CF0,60
^FO50,50^GB100,100,100^FS
^FO75,75^FR^GB100,100,100^FS
^FO93,93^GB40,40,40^FS
^FO220,50^FDIntershipping, Inc.^FS
^CF0,30
^FO220,115^FD1000 Shipping Lane^FS
^FO220,155^FDShelbyville TN 38102^FS
^FO220,195^FDUnited States (USA)^FS
^FO50,250^GB700,3,3^FS

^FX Second section with recipient address and permit information.
^CFA,30
^FO50,300^FDJohn Doe^FS
^FO50,340^FD100 Main Street^FS
^FO50,380^FDSpringfield TN 39021^FS
^FO50,420^FDUnited States (USA)^FS
^CFA,15
^FO600,300^GB150,150,3^FS
^FO638,340^FDPermit^FS
^FO638,390^FD123456^FS
^FO50,500^GB700,3,3^FS

^FX Third section with bar code.
^BY5,2,270
^FO100,550^BC^FD12345678^FS

^FX Fourth section (the two boxes on the bottom).
^FO50,900^GB700,250,3^FS
^FO400,900^GB3,250,3^FS
^CF0,40
^FO100,960^FDCtr. X34B-1^FS
^FO100,1010^FDREF1 F00B47^FS
^FO100,1060^FDREF2 BL4H8^FS
^CF0,190
^FO470,955^FDCA^FS

^XZ

The results (when paired with the Render Image step) are displayed like so: