[dataimport, migration] more fixes in the spirit of a6c32edabc8d:
[entity, metadata] huuum, use resolvable url as cwuri... And fix existing ones.
Closes #3390388
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html