✨ Add errorprone and fix warnings/errors

The compiler will also treat all warnings as errors from now on.

cloud-minecraft/cloud-velocity/src/main/java/cloud/commandframework/velocity/CloudInjectionModule.java

@@ -68,6 +68,7 @@ public final class CloudInjectionModule<C> extends AbstractModule {
     }
 
     @Override
+    @SuppressWarnings({"unchecked", "rawtypes"})
     protected void configure() {
         final Type commandTreeType = Types.newParameterizedType(CommandTree.class, this.commandSenderType);
         final Type commandExecutionCoordinatorType = Types.newParameterizedType(CommandExecutionCoordinator.class,

cloud-minecraft/cloud-velocity/src/main/java/cloud/commandframework/velocity/VelocityCommandManager.java

@@ -77,6 +77,7 @@ public class VelocityCommandManager<C> extends CommandManager<C> {
      * @param backwardsCommandSenderMapper Function that maps the command sender type to {@link CommandSource}
      */
     @Inject
+    @SuppressWarnings("unchecked")
     public VelocityCommandManager(
             final @NonNull ProxyServer proxyServer,
             final @NonNull Function<@NonNull CommandTree<C>, @NonNull CommandExecutionCoordinator<C>> commandExecutionCoordinator,

cloud-minecraft/cloud-velocity/src/main/java/cloud/commandframework/velocity/VelocityCommandPreprocessor.java

@@ -31,7 +31,7 @@ import org.checkerframework.checker.nullness.qual.NonNull;
  * Command preprocessor which decorates incoming {@link cloud.commandframework.context.CommandContext}
  * with Velocity specific objects
  *
- * @param <C>
+ * @param <C> Command sender type
  * @since 1.1.0
  */
 final class VelocityCommandPreprocessor<C> implements CommandPreprocessor<C> {

cloud-minecraft/cloud-velocity/src/main/java/cloud/commandframework/velocity/VelocityPluginRegistrationHandler.java

@@ -55,6 +55,7 @@ final class VelocityPluginRegistrationHandler<C> implements CommandRegistrationH
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public boolean registerCommand(final @NonNull Command<?> command) {
         final CommandArgument<?, ?> argument = command.getArguments().get(0);
         final List<String> aliases = ((StaticArgument<C>) argument).getAlternativeAliases();

cloud-minecraft/cloud-velocity/src/main/java/cloud/commandframework/velocity/arguments/PlayerArgument.java

@@ -179,6 +179,8 @@ public final class PlayerArgument<C> extends CommandArgument<C, Player> {
 
     public static final class PlayerParseException extends ParserException {
 
+        private static final long serialVersionUID = -4839583631837040297L;
+
         private PlayerParseException(
                 final @NonNull String input,
                 final @NonNull CommandContext<?> context

cloud-minecraft/cloud-velocity/src/main/java/cloud/commandframework/velocity/arguments/ServerArgument.java

@@ -172,6 +172,8 @@ public final class ServerArgument<C> extends CommandArgument<C, RegisteredServer
 
     public static final class ServerParseException extends ParserException {
 
+        private static final long serialVersionUID = 9168156226853233788L;
+
         private ServerParseException(
                 final @NonNull String input,
                 final @NonNull CommandContext<?> context