[selectors, facet] make is_instance and other EClassSelector subclass gather entity classes from 'select' and 'filtered_variable' context information. Closes #1796732 This allow for instance to use the filter form on rqlst where the filtered variable is not selected

if versions_map['cubicweb'][0] == (3, 7, 4):
    config['http-session-time'] *= 60
    config['cleanup-session-time'] *= 60
    config['cleanup-anonymous-session-time'] *= 60