[web/application] remove `path` argument from CubicwebPublisher methods
Path can actually be accessed from `req` object. This allows to avoid duplicating
this information.
This cset prepares the next ones that aim at adding the language as a prefix of the
relative path.
usr/lib/python2*/*-packages/cubicweb/web
usr/lib/python2*/*-packages/cubicweb/wsgi
usr/share/cubicweb/cubes/shared/data
usr/share/cubicweb/cubes/shared/wdoc