Fixing chat parsing issues that result in wrong files

[goncalomoita]

Improved parsing function (parse_chat) which directly affects the file generation process.

"parse_chat", which is located in gpt_engineer/chat_to_files.py, is now able to discern filenames by searching in specific areas near the code block.
Rather than performing filename pattern matching on the entire prompt completion output, the new approach looks for
the filename in logical spots (just like a human would).

Also included a tests file tests/test_chat_parser.py, that checks if parse_chat is working properly for a plethora of code formatting techniques.

[NoCLin]

could you please take a look and test it? #94

[goncalomoita]

I like this idea for self-reviewing and improving the code itself. I've talked about using this for parsing in #35:

"""
I thought about the problem of ensuring a consistent format when deciding whether or not to improve this parser. My initial thought was "Does better parsing make sense? Can I fix this with a "self-review" call to a LLM? Should I call the LLM just to find what the filenames are?".
Those are possible solutions but they add performance overhead, since you have to wait for another inference, and ultimately cost.
"""

But I encourage you to do this for a "self-reviewer", a sort-of senior programmer that fixes the mistakes of a junior 😆