FAQ: Add a native-lib-loader case for multiple platform support

Provide an example how to use native-lib-loader for multiple platforms.
It is about how to use nar packaging.
Example: Add it0026-native-lib-loader

Provide an integration-test to use native-lib-loader.
Usage: Add "Create a JNI Library using native-lib-loader"

Provide code snippets to use native-lib-loader in pom.xml.