Recommend renaming python file if python file it overwrites builtins

[DonJayamanne]

We find that a lot of users run into this when creating python files using reserved names like sys.py/os.py/random.py.
As a result Python runtime will import the user defined files and it could fall over.

Solution:
If kernel startup fails and we detect such a scenario then recommend renaming that file.

[DonJayamanne]

Solution:

• We can detect the import error message from the stderr when kernel fails to launch
• Ensure a python file with the name of a built exists in the stderr & exists in workspace folder (thats not in the python env)
• If above conditions are met recommend deleting the above

This is could be the start of kernel doctor