Do not apply a resource pack that has already been applied (#1236)

* Do not apply a resource pack that has already been applied

* Throw IllegalStateException in case of applying a resource pack already applied from the API

* Updated some dependencies

* Added support for ServerResourcePackSendEvent resource pack modification

api/src/main/java/com/velocitypowered/api/proxy/player/ResourcePackInfo.java

@@ -54,8 +54,7 @@ public interface ResourcePackInfo extends ResourcePackRequestLike {
    *
    * @return the hash if present or null otherwise
    */
-  @Nullable
-  byte[] getHash();
+  byte @Nullable [] getHash();
 
   /**
    * Gets the {@link Origin} of this resource-pack.