feat: add a check to analyze malicious Python packages

[Yao-Wen-Chang]

PR Message:

Implemented PyPI's heuristics check to detect suspicious packages using seven key heuristics.

TODO List:

• Implement PyPI's heuristics check to detect the suspicious packages with seven heuristics
• Implement confidence policy
• Implement PyPI package registry
• Design the DB table to store the proper result
• Create src/macaron/malware_analyzer/ directory and move this check there.
• Update documentation to reflect the new heuristics and their usage
• Write unit tests to ensure the reliability and accuracy of the heuristics implementation

[tromai]

@Yao-Wen-Chang When you address an issue mentioned in a comment, you can put the link to the commit next to the comment indicating that it has been resolve. Something like this would be extremely helpful for my review. Thanks!

Fixed this in https://github.com/oracle/macaron/pull/750/commits/d6684088dbe7792731240709d73a17de1eba73ad