Plugin accessor for the build-scan plugin

[eskatos]

This:

plugins {
    `build-scan`
}

would apply the latest version of the Build Scan plugin available when releasing the Kotlin DSL.

The documentation for the accessor would point to the Build Scan Plugin User Manual

Like with any other plugin accessors one can then specify a version if need be:

plugins {
    `build-scan` version "1.9"
}

[eskatos]

Here's what the accessor would look like:

/**
 * The `build-scan` plugin.
 *
 * Visit the [Build Scan Plugin User Manual](https://docs.gradle.com/build-scan-plugin/) for additional information.
 *
 * Equivalent to <code>id("com.gradle.build-scan") version "1.8"`</code>.
 * You can also use e.g. <code>`build-scan` version "1.7.1"</code> if you want to use a different version.
 */
val PluginDependenciesSpec.`build-scan`: PluginDependencySpec
    get() = id("com.gradle.build-scan") version "1.8"