Improve Add Dockerfiles to Django projects

[ucheNkadiCode]

Scenario:

User selects add dockerfiles to workspace
Select Application Platform -> no change
Python: Django -> no change
Choose the app's entry point (e.g. manage.py, app.py)

My suggestion is to add a dialog so the user can (optionally) select where their wsgi.py file is in their application. We should try to look for wsgi file in the root folder as well as the [workspace name][workspace_folder of same name]\wsgi.py > ...(e.g. wsgi.py, asgi.py) and pop those to the top, but then also allow them to type it in

Port: 8000 -> no change

If they choose manage.py, need to attempt to locate the wsgi.py, but if they choose wsgi.py or asgi.py then use the path exactly

[bwateratmsft]

We still need them to pick manage.py. That can't change, it is necessary for debugging to work properly. I'll alter the logic to better find ASGI/WSGI files. The only variability I've seen so far in common Django apps is in the subfolder name; I think it's sufficient to try to autodiscover WSGI files in other subfolders.

[bwateratmsft]

This is now released in Docker extension version 1.20.0.