chore(cleanup)!: Remove redundant callback types, move storage.ts to …

[ddelgrosso1]

…calling gaxios

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Fixes # 🦕

[ddelgrosso1]

Gigantic WIP / PoC

[ddelgrosso1]

IIUC the bulk of this PR is refactoring all the common options to "Storage-Transport" and wiring everything back together? If thats right, it would be helpful to add context in the StorageTransport docs.

Also, if this is the case, maybe create a seperate PR that introduces the concept of "storage-transport", and then the PRs after that can incrementally refactor specific files that need to be refactored (e.g. ACL, Bucket, HMAC, etc.)

Sort of. StorageTransport is replacing the mixture of transport level options and functionality that was spread across several files (Service, ServiceObject, util).

I think we are a bit too far past just introducing Storage Transport. I think at this point our best path forward is to merge this into the feature branch and then do as you suggest and work on each file / section individually.