[feature]: add nesting_type to concurrency operations

[zhongkechen]

Issue #, if available:

• fixes: [Feature]: add nesting option to Map/Parallel #350

Description of changes:

• added a new nesting mode parameter to map and parallel operation
• added a new checkpoint mode parameter to child context operation

============================= test session starts ==============================
collecting ... collected 1 item

examples/test/map/test_map_operations_flat.py::test_map_operations 

========================= 1 passed, 1 warning in 0.55s =========================
PASSED [100%]

============================= test session starts ==============================
collecting ... collected 1 item

examples/test/parallel/test_parallel_flat.py::test_parallel_flat 

======================== 1 passed, 3 warnings in 1.55s =========================
PASSED  [100%]

TESTING_SDK_BRANCH=nest_type

Fixed integration workflow.

examples/test/parallel/test_parallel_flat.py::test_parallel_flat PASSED  [ 97%]

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.