UUID: pyCSW

[etj]

We need CSW entrypoints for pre-filtered CSW queries.

At the moment the CSW service is mapped through this URL definition:

url(r'^csw$', views.csw_global_dispatch, name='csw_global_dispatch'),

We need to enable calls for URLs ending with csw/{IPA}.
If the IPA code exists in PubblicaAmminstrazione.ipa, we want to prefilter CSW results by fileIdentifier field beginning with ipa:.
pyCSW pre-filtering is documented at https://docs.pycsw.org/en/2.6.0/repofilters.html.