[NEW PORT] cad/py-ezdxf: Create and modify DXF drawings

A Python package to create and modify DXF drawings, independent from the DXF
version. You can open/save every DXF file without losing any content (except
comments), Unknown tags in the DXF file will be ignored but preserved for
saving. With this behavior it is possible to open also DXF drawings that
contains data from 3rd party applications.

PR: 248203
Submitted by: Neal Nelson
Approved by: tcberner (mentor)
Differential Revision: https://reviews.freebsd.org/D25890