Add support for getting annotation from parent class/method/parameter#429

This will allow use cases such as having a parent class with `@CommandAlias` so I do not have to add `@CommandAlias("mv")` to 20 different command classes. ```java @CommandAlias("mv") public abstract class CoreCommand extends MultiverseCommand { // ... } class CloneCommand extends CoreCommand { @Subcommand("clone") void onCloneCommand(...) { } } ``` And this will also me to create aliases to a command by extending the command class as such: ```java class LegacyAlias extends CloneCommand { @Override @CommandAlias("mvclone") void onCloneCommand(...) { super.onCloneCommand(...); } } ```