Rewrite Lingua in Java

[pemistahl]

As I most probably won't have much time in the future to maintain Lingua due to my family life, let's rewrite Lingua in Java as long as I have time. My hope is to attract more people from the Java community to use and improve this library in the future. Having a plain Java library should simplify long-term maintenance as well due to Java's backwards compatibility.

Kotlin is a great language but a second-class citizen on the JVM. Its use did not provide significant advantages compared to a plain Java implementation. I have doubts whether Kotlin will continue to have a bright future as both Java as a language and the JVM get significantly better, especially with the release of Java 21.