[Feature] Gradle Plugin

[Nillerr]

Purpose

As Mockative has grown to support more and more features, the way you apply Mockative to your project through Gradle has also grown. To make this process easier, and increase adoption, a Gradle plugin would be beneficial. The API could be something like the following:

plugins {
    id("io.mockative")
}

mockative {
    optIn("io.github.*", "kotlinx.cinterop.ExperimentalForeignApi")
}