Make it possible to force CLI rendering

[pilif]

For development of APIs, it would be very nice if there was a way to make tracy emit its CLI formatted error messages in some cases (in my case it would be in dev mode, when the user agent is curl).

I looked at the code and I can nearly force it to go the correct route by affecting global state one way or another, but in the very end, there's Helpers::detectColors() which calls Helpers::isCli() which looks at PHP_SAPI which I cannot fake.

It would be cool if there was a way where I could put tracy "hey - this request, even though it's made through a server - will end up outputting on my terminal, so please go in CLI mode"