[ldapfeed] make code compatible with ldap3>=2
* Some constants have been renamed.
* Directly bind when data-cnx-dn/data-cnx-password are provided, some servers,
including ours require this.
* Use raise_exceptions=True to avoid ignored ldap errors
* raise in case of failed anonymous bind
* do not search for "dn" attribute because this raise an "invalid attribute"
with new ldap3 versions
* Password is now returned as bytes, so no longer need to encode them before crypt.
* modification_date is now returned as a datetime object
Co-Authored-By: Philippe Pepiot <philippe.pepiot@logilab.fr>
Closes #16073071
### Requirements for tests in various cubicweb/**/test directories. ###
## shared by several test folders
docutils
webtest
## cubicweb/test
Pygments
pycryptodomex
#fyzz XXX pip install fails
## cubicweb/devtools/test
flake8
## cubicweb/hooks/test
psycopg2-binary
## cubicweb/pyramid/test
pyramid >= 1.5.0
waitress >= 0.8.9
wsgicors >= 0.3
pyramid_multiauth
repoze.lru
## cubicweb/sobject/test