[server] extract creating a new cnxset in a _new_cnxset() helper
So we can move logic specific to _CnxSetPool here.
:mod:`cubicweb.pyramid`
=======================
.. automodule:: cubicweb.pyramid
.. autofunction:: wsgi_application_from_cwconfig
.. autofunction:: wsgi_application
.. toctree::
:maxdepth: 1
:glob:
pyramid/*