Spring Security Use Kotlin DSL Marker Annotations to prevent scope leaking

Summary

Currently, in the Kotlin DSL, function autocompletion is not limited to their specific scope. This leads to configurations like the one below, which should not be allowed.

http {
    authorizeRequests {
        authorizeRequests {
        }
    }
}

This issue is migrated from https://github.com/spring-projects-experimental/spring-security-kotlin-dsl/issues/19.