Prompt for connection strings on `func new`

Today when creating a new function to connect to something like blob, we generate code but don’t do much to help the user wire up their function or setup the function.json correctly. VS code uses the approach of (optionally) prompting for a few of the values at the time of create. So for storage it will ask for the container name and the connection string and then populate the function.json and local.settings.json for the user.

The core tools should have something similar.

Start at the `func new` command and trace how generated code, `function.json`, and `local.settings.json` are currently created. Compare the desired storage flow with the issue’s VS Code description; done means the command can optionally collect the container name and connection string and populate the relevant configuration.

Written by the indexing model from the issue text.