Add first-class support for included/composite builds

Right now, included builds are treated like regular projects, which means their versions are separate from the the project that includes them.

While this is great when you want to keep the projects decoupled, it’d be great to also have the option to share the setup, the versions.properties file, and have runs of the refreshVersion task also refresh the versions from all included builds that opt-in to this behavior.

[NikkyAI]

dirty experiment to see if refreshVersions can automatically set up task dependencies on refreshVersions in included builds

gradle.rootProject {
    afterEvaluate {
        val task = gradle.includedBuilds.firstOrNull()?.task(":refreshVersionsDDDDsjdfhdsiuf")!!
        logger.lifecycle("task: $task")
        val ourTask = tasks.create("doStuffYouKnow")
        val dependsOn = ourTask.dependsOn
        ourTask.dependsOn(task)
        try {
            ourTask.taskDependencies.getDependencies(ourTask)
        } catch (e: Exception) {
            ourTask.setDependsOn(dependsOn)
            System.err.println("our marvellous task is not there ;) :P :D :D :D")
        }
    }
}

[LouisCAD]

I don’t see how the version entry usage comments would be removed.