Support a Kotlin wrapper

[DestBro]

Tribuo lacks Kotlin wrapper support, which makes it harder and less idiomatic to use in Kotlin projects compared to other ML libraries.

Add an official Kotlin wrapper with idiomatic APIs (extension functions, null-safety, data classes, etc.) to make Tribuo seamless for Kotlin developers.

I considered writing custom wrappers, but this is limited and not robust. Also I used other libraries like Smile, which already provides a Kotlin wrapper (https://haifengl.github.io/api/kotlin/index.html)