[Storage] Adopt a response hook param for headers

[annatisch]

Currently we're returning the response headers directly in some cases and not in others.
We should change the behaviour to never return the response headers - rather have each function take an optional callable that can accept the headers.

This is the approach used by cosmos.

[tasherif-msft]

Hi @annatisch, I will close this issue since we GA'd and this is no longer possible :/