The kotlin-native-shared artifact includes API allowing
us to work with K/N platforms, hosts, distribution etc.
This patch replaces a dependency on kotlin-native-utils
containing copies of such classes with a dependency on
published kotlin-native-shared in the Gradle plugin and
bundles kotlin-native-shared into the Gradle plugin jar.
With gradle > 5.0 `publish()` helper call should be done before
`noDefaultJar()` or any other artifact hacks, otherwise singing plugin doesn't sign any jars
Vyacheslav Gerasimov