PY-23167: Support packages with out __init__.py for Py2 test runners

You can use Python path like "spam.eggs" where "spam" does not have
__init__.py. This scheme is used by runners to report test names.

For Py3 it works, but not for Py2.
``_jb_runner_tools`` contains logic to workaround it

python/testData/testRunner/env/pytest/folder_no_init_py/test_test.py

@@ -0,0 +1,8 @@
+
+
+def test_test():
+    assert False
+
+
+def test_2_test():
+    pass