Feel free to create and publish a new plugin implementing the LibraryRetriever extension point.
Why not!
Any recommended read to know how to start writing my first Jenkins plugin?
We started working on the implementation of this plugin internally. We'll see later how to make it open source.
The plugin has been released: https://github.com/AmadeusITGroup/workflow-cps-global-lib-http-plugin Feel free to consider this issue as solved.
Thanks!