As a developer, pack build exits cleanly and quickly on ctrl-c when an image is pulling

[sclevine]

Acceptance Criteria
When I pack build
And An image starts pulling
And I ctrl-c
Then It exits immediately
And I don't observe network traffic

[ekcasey]

It seems like this works now that the pull logic has been pulled into pack but it does print a fairly raw (ugly?) error. Are we okay we this? If not what do we want it to look like?

./pack build -p ./acceptance/testdata/node_app/ --builder gcr.io:443/cncf-buildpacks-ci/packs/samples:3.0.0-alpha.3-build.14 node/app
Using user-provided builder image gcr.io:443/cncf-buildpacks-ci/packs/samples:3.0.0-alpha.3-build.14
Pulling builder image gcr.io:443/cncf-buildpacks-ci/packs/samples:3.0.0-alpha.3-build.14 (use --no-pull flag to skip this step)
^CERROR: error during connect: Post http://%!F(MISSING)var%!F(MISSING)run%!F(MISSING)docker.sock/v1.38/images/create?fromImage=gcr.io%!A(MISSING)443%!F(MISSING)cncf-buildpacks-ci%!F(MISSING)packs%!F(MISSING)samples&tag=3.0.0-alpha.3-build.14: context canceled

[mgibson1121]

This story passes acceptance