Streamline the deployment for event grid triggers

[mistymadonna]

PaulYuk: when u deploy the function & we know you're using the event grid based blob trigger can we facilitate adding the event subscription right after

Deepthi: setting up event subscription is very hard

Discussion on 10/17 SFI changes in Functions

Note, this newer mechanism for BlobTrigger with EventGrid source is documented in more detail here

Here's a script workaround that automates setting the EG subscription