Add classpath collision detection feature/task

[jjohannes]

A feature that checks the (runtime) classpath for duplicated classes. I think this would fit well into the scope of the detection plugin. Although until now, we do not have tasks in the plugin. So this is certainly something to discuss first.

• In Android projects, this feature is already delivered as part of AGP
• For Java projects, I currently recommend io.fuchs.gradle.classpath-collision-detector as an additional plugin for this.