Introduce a Kotlin Multiplatform Mobile library

Start by examining the current etebase-java implementation and how its Rust code generates classes. Research Kotlin Multiplatform Mobile support for Android, the JVM, and iOS, including native DLL loading. Done means a working library can use shared Kotlin code with platform-specific networking across the proposed targets.

KMM is a way to write code that runs on Android, iOS, native and the JVM. Common code is written in Kotlin and platform-specific code can then be used to implement lowlevel details (in this case networking).

The current etebase-java java implementation only works on Android. Rewriting it could make it possible to run it on Android and the JVM. Taking it a step further one could also include iOS support.

I am not familar with how native DLL loading would work in this case. I took a glimse at the code in this repository but do not really understand how it works to be honest. Does the Rust code generate all the necessary classes on built (deterministically)?