Fix serialization and desrialization the pythonjob data

[superstar54]

This PR improve the PythonJob:

• handle 'namespace' socket when derializatoin
• for importable functions, import them directly; for locally defined functions, use their source code.
• bump node-graph to 0.1.0, so that the link_limit is 1e6 and identifier is workgraph.namespace for var_args and var_kwargs

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 88.09524% with 10 lines in your changes missing coverage. Please review.

Project coverage is 80.68%. Comparing base (5937b88) to head (a614899). Report is 71 commits behind head on main.

Files with missing lines	Patch %	Lines
aiida_workgraph/tasks/pythonjob.py	84.61%	8 Missing :warning:
tests/test_python.py	91.66%	1 Missing :warning:
tests/test_socket.py	85.71%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #308 +/- ## ========================================== + Coverage 75.75% 80.68% +4.93% ========================================== Files 70 66 -4 Lines 4615 5089 +474 ========================================== + Hits 3496 4106 +610 + Misses 1119 983 -136 ``` | [Flag](https://app.codecov.io/gh/aiidateam/aiida-workgraph/pull/308/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam) | Coverage Δ | | |---|---|---| | [python-3.11](https://app.codecov.io/gh/aiidateam/aiida-workgraph/pull/308/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam) | `80.60% <88.09%> (+4.93%)` | :arrow_up: | | [python-3.12](https://app.codecov.io/gh/aiidateam/aiida-workgraph/pull/308/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam) | `80.60% <88.09%> (?)` | | | [python-3.9](https://app.codecov.io/gh/aiidateam/aiida-workgraph/pull/308/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam) | `80.64% <88.09%> (+4.90%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aiidateam#carryforward-flags-in-the-pull-request-comment) to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.