Escape LDAP characters

When a user has ( in its DN, the users page raise a 500. We should escape characters when building ldap filters. We should do the same for DNs.

https://www.python-ldap.org/en/python-ldap-3.3.0/reference/ldap-dn.html?highlight=escape#ldap.dn.escape_dn_chars

https://www.python-ldap.org/en/python-ldap-3.3.0/reference/ldap-filter.html?highlight=escape#ldap.filter.escape_filter_chars