Update pydevd_console_output.py

[tanmaychimurkar]

Renaming usage of str keyword (reserved by Python) to string for easier understanding of code. Interestingly, I found the warning via PyCharm itself :)

As always, a big thanks to the JetBrains team

[tanmaychimurkar]

Hi Team,

Is there a possibility of getting this reviewed and merge? Because I'm not sure if this falls along with the design style of the IntelliJ-community edition IDE. If it creates conflicts with the design style, I can also close this PR :)