Little refactor to allow imports from python instead of cli/subprocess

[wuodar]

Currently, there is no real way to import deduplication algorithm and use it as a dependency in my python code without almost totally rewriting the content of main (the code under if __name__ == "__main__") - I think it would be beneficial to simply extract logic to sth. like main() function, and then in real "main" just construct parser, and pass parsed parameters to main.