[web/test] drop dependency on third party cubes Drop dependency on cubicweb-file, cubicweb-blog and cubicweb-tag for cubicweb/web/test Copy required parts of cubes (schema, entities, views and hooks) into cubicweb/web/test/data/cubicweb-<cube> that make tests pass.

cubicweb source: source-is-missing cubicweb/web/data/jquery.flot.js line length is * characters (>512)