Kotlin multiplatform + Android support

[DariusIMP]

In this PR we reestructure the project in order to:

• Convert the project into a kotlin multiplatform project providing support for both Android and JVM targets
• Provide support to easily publish the library to maven for Android and JVM (checkout the README updates)
• We automatize the compilation of the ZenohJNI native library (the user doesn't require anymore to run cargo build on their own, the gradle scripts are configured to do it if needed)
• We provide different behaviour depending on the target (for instance a JVM target requires loading the native library programmatically depending on the platform, while Android doesn't require it (the Android platform handles it))

This PR relies on three gradle plugins:

• Kotlin multiplatform plugin
• Rust Android Gradle plugin
  • This later causes the native library to be compiled with the Android NDK
  • It is configured to:
    • Build against the following targets supported by the plugin:

       'arm',
       'arm64',
       'x86',
       'x86_64'
    

    • Automatically load the binaries into the generated aar file.
• Maven publish plugin for publication.