refactor: purl.fullname -> lookupName

lib/datasource/cargo/index.js

lib/datasource/docker/index.js

lib/datasource/github/index.js

lib/datasource/go/index.js

lib/datasource/metadata.js

lib/datasource/npm/releases.js

lib/datasource/nuget/index.js

lib/datasource/orb/index.js

lib/datasource/packagist/index.js

lib/datasource/pypi/index.js

lib/datasource/readme.md

lib/datasource/rubygems/releases.js

lib/datasource/terraform/index.js

lib/manager/bundler/artifacts.js

lib/util/purl.js

test/datasource/__snapshots__/go.spec.js.snap

test/datasource/cargo.spec.js

test/datasource/docker.spec.js

test/datasource/npm/index.spec.js

test/datasource/rubygems/index.spec.js