Guice core - dependency injection w/ Guice

This pull request adds dependency injection to the Core project of Alitheia Core. Every service is now packaged as a Guice module and is injected as such. Some classes that are instantiated in a non-standard way or outside the reach of the Alitheia Core project (e.g. by utilized frameworks) don't participate in the dependency injection yet. This refactoring removes the God class status of the AlitheiaCore class in the core package.