[Kotlin] language keywords (e.g. 'break') can not be used as model names

Description

When I use the codegen to produce Kotlin code for my "break" model, it produces uncompilable code

/**
 * Break details.
 * @param duration Duration of the break
 * @param endDate Date when the break ended
 * @param startDate Date when the break started
 */
data class `break` (
    /* Duration of the break */
    val duration: java.math.BigDecimal,
    /* Date when the break started */
    val startDate: java.time.LocalDateTime,
    /* Date when the break ended */
    val endDate: java.time.LocalDateTime? = null
) {

}

Swagger-codegen version

io.swagger.codegen.v3:swagger-codegen-cli:3.0.0

Suggest a fix/enhancement

What the Java generator does is rename to ModelBreak

Start with the Kotlin code generator and compare how the Java generator renames a model named "break" to "ModelBreak". Run the code generator using a model named "break", then verify that the generated Kotlin model compiles and that the model name is safely renamed.