[web] Disable 'concat-resources' by default (closes #3670503)
It makes debugging harder and it can actually *break* working JS or CSS files.
This is the first step towards complete removal.
usr/lib/PY_VERSION/*-packages/cubicweb/entities/
usr/lib/PY_VERSION/*-packages/cubicweb/ext/
usr/share/cubicweb/cubes/
usr/lib/PY_VERSION/*-packages/cubicweb/*.py