from camel case to screaming snake case

Strings.kt

fun String.fromCamelCaseToScreamingSnakeCase(): String {
    val builder = StringBuilder()
    for(i in 0 until length) {
        if(i > 0 && i < length-1 && this[i].isUpperCase())
            builder.append("_")

        builder.append(this[i].toUpperCase())
    }
    return builder.toString()
}