2387: JSONPath eval(string,string) issue fix

[swapdewalkar]

What this PR does / why we need it?

Address the issue:
alibaba/fastjson#4493
#2387

Summary of your change

If you are passing string as root object to eval its fail as current eval(Object ..) method can not handle it.
Add new method and using extract method to handle this case.
Also added the test case

Please indicate you've done the following:

• Made sure tests are passing and test coverage is added if needed.
• Made sure commit message follow the rule of Conventional Commits specification.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed.

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