improve: exract Code Node provider for each supported scripting language

[bowenliang123]

Description

• extract common CodeNodeProvider for Javascript and Python, to increase the cohesion for each supported programming language code node

Type of Change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update, included: Dify Document
• [x] Improvement, including but not limited to code refactoring, performance optimization, and UI/UX improvement
• [ ] Dependency upgrade

How Has This Been Tested?

• no feature introduced, and all changes covered in exited intgration tests for CodeExecutor

Suggested Checklist:

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings
• [x] I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods
• [ ] optional I have made corresponding changes to the documentation
• [ ] optional I have added tests that prove my fix is effective or that my feature works
• [ ] optional New and existing unit tests pass locally with my changes

[bowenliang123]

cc @Yeuoly @takatost

[Yeuoly]

Please wait for #4231 to be merged into main, thx!

[bowenliang123]

As #4231 was merged and this PR has been rebased, it is ready for review. Please have a check. @Yeuoly

[bowenliang123]

Hi @Yeuoly , I have fixed the JSON serialization problem as you reported offline and added proper tests for it. Please have a look.

[bowenliang123]

Thanks~