refactor(extractor): export ParseJsonPath function

[Belyenochi]

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

2. What is the scope of this PR (e.g. component or file name):

extractor/parser.go

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

Export ParseJsonPath function to allow external packages to validate JSONPath expressions using the same parsing logic, ensuring consistency between validation and runtime.

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

Existing tests in extractor/extractor_test.go cover the parsing logic.

6. Release note

None

[github-actions]

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[Belyenochi]

I have read the CLA Document and I hereby sign the CLA

[Belyenochi]

I have read the CLA Document and I hereby sign the CLA

[zoumo]

LGTM