refactor: defer isX upgrade classifications

lib/manager/docker/package.js

lib/manager/npm/versions.js

lib/workers/branch/index.js

lib/workers/repository/onboarding/pr/pr-list.js

lib/workers/repository/process/write.js

lib/workers/repository/updates/branchify.js

test/manager/docker/__snapshots__/package.spec.js.snap

test/manager/npm/__snapshots__/versions.spec.js.snap

test/workers/branch/index.spec.js

test/workers/repository/onboarding/pr/pr-list.spec.js

test/workers/repository/process/write.spec.js

test/workers/repository/updates/branchify.spec.js