Feature/332 fix middleware [2.0]

[jamshale]

When the logging middleware function called call_next and it experienced an exception then the response object is not available and would throw a response not available in locals exception that would hide the real exception. It is un-catchable in the middleware.

This checks if response object exists in the locals in the finally block, and if it does then logs the message, and if it doesn't then it assumes it's an exception and looks in traceback, logs the stack trace and returns a 500 response with a more informative message.

The json logger didn't work with the stacktrace from call_next, which would mean the production stack traces would be invisible. Now this explicitly logs the stacktrace from the middleware if LOG_WITH_JSON is True.

The stacktrace for the json format (production) is a bit ugly but I can't think of a way to really make them nice so I just log it as one big string.

[esune]

👍🏻