Add missing relation types items in schema global variables
Some of these global variables are used, in particular, to control schema
views (web/views/schema.py).
While they are currently not properly documented (see #3360868), their
definition are currently incomplete (e.g. one could reasonably expect to find
``cw_schema`` in ``SYSTEM_RTYPES``).
Closes #3486114.
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.*/data/database/.*\.sqlite
.*/data/database/.*\.config
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.*/data/ldapdb/.*
^doc/html/
^doc/doctrees/
^doc/book/en/devweb/js_api/
data/pgdb/