Consider renaming AZURE_STORAGE_CONN_STRING to AZURE_STORAGE_CONNECTION_STRING

[rrnewton]

This is a migration of VSTS 127.

Existing Azure CLI tools use AZURE_STORAGE_CONNECTION_STRING, so it would be good to standardize on that and avoid confusion.

For backwards compatibility with the existing AMBROSIA release, it could look for both and use the current "CONN" version if "CONNECTION" is not found.

[lovettchris]

Better still, AZURE_STORAGE_CONNECTION_STRING is way too general it should be called "AMBROSIA_STORAGE_CONNECTION_STRING"

[rrnewton]

Agreed that this is more general and also more hygienic.

But is there a scenario where one would want to have the azure CLI talk to one AZURE_STORAGE_CONNECTION_STRING, and have ambrosia use a different AMBROSIA_STORAGE_CONNECTION_STRING?