* Derive jail name from class name and method name, instead of just
method name. This change reduces the chances of different tests
clashing.
Old: 'jail_test_one'. New: 'pytest:TestExampleSimplest:test_one'
* Simplify vnetX_handler() method signature by skipping obj_map (unused)
and pipe. The latter can be accessed as the vnet property.
* Add `send_object()` method as a pair to the `wait_object` inside the
VnetTestTemplate class.
* Add `test_id` property to the BaseTest method. Previously it was
provided only for the VnetTestTemplate class. This change makes
the identifier easily accessible for all users.
MFC after: 2 weeks