Refactor the output-related code to support structured output

by zym for strace

In this proposal, I want to make it easier to parse the strace’s output. Since the well-structured output in JSON is much better than the current classical output for program analysis. I am going to import a new feature to strace to make it support output in JSON. In my method, I will refactor the currently output-related code in strace and then import a totally-new framework to decouple the currently tightly-coupled high-level format and the low-level output functions.