Project Improvement Release (1.1.0)

• Add a new method to the RNVAPI class that allows passing a custom OkHttpClient instance.
• Update all project and build dependencies to the latest version.
• Shade all project dependencies to io.github.krymonota.rnvapi.shaded.* for improved compatibility with third-party projects.
• Change final file name from RNV-API.jar to rnv-api-{version}.jar.
• Relocate all source and example classes to match common conventions: src/main => src/main/java, src/examples => src/examples/java
• Add some JUnit tests.
• Add Checkstyle coding conventions and tests.
• Add license information to all classes and pom.xml.
• Add a package-info.java file to each package and comments to each class.
• Add a default build goal to pom.xml.
• Add README.md and LICENSE to the final file.
• Enhance pom.xml by introducing some new informative tags.