Supporting changes for new docker client (#2344)
* integration test for secrets
* move credentials logic off command.Command
the credential stuff isn't tied to the docker client. This moves logic to helper functions that both clients can use
* move CreateTarFile & CreateAptTarFile to helpers
The monobase helpers from command.Command were calling docker run, instead have them call the run functions on the client since the logic doesn't depend on client implementation
* error helpers
helpers to map errors from different backends to known types. needed to support both clients
* more docker integration tests
* Update go.mod
* fix for merge flub and correct new client func name
* remove some code that's only used in the sdk client
