textproc/zxing-cpp: switch upstream and update to 1.0.8

Most Linux Distros seem to ship [1] from the nu-book upstream [2].
For net/kaidan 0.50 this upstram is required.

Give maintainership to kde@.

[1] https://repology.org/project/zxing-cpp-nu-book/versions
[2] https://github.com/nu-book/zxing-cpp

PR: 246508
Approved by: yuri (maintainer)