convert API/server tests to mockito (#8848)

* convert API tests to mockito

* convert server tests to mockito

* add co-author

patches/server/0957-Remove-CraftItemStack-setAmount-null-assignment.patch

@@ -1,30 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Josh Roy <joshroy126@gmail.com>
-Date: Mon, 23 Jan 2023 19:19:01 -0500
-Subject: [PATCH] Remove CraftItemStack#setAmount null assignment
-
-This creates a problem with Paper's item serialization
-api where deserialized items, which are internally
-created as a CraftItemStack, will be completely lost if
-#setAmount(0) is invoked (since the underlying handle
-is set to null), while a regular Bukkit ItemStack
-simply sets the amount field to zero, retaining the
-item's data.
-
-Vanilla treats items with zero amounts the same as items
-with less than zero amounts, so this code doesn't create
-a problem with operations on the vanilla ItemStack.
-
-diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
-index 3e5abea2f814a0a364cf87ff4ce1b1718ba2ddac..97c5a72096ac0fd0b08a397466486014cfea4579 100644
---- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
-+++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftItemStack.java
-@@ -146,7 +146,7 @@ public final class CraftItemStack extends ItemStack {
-         }
- 
-         this.handle.setCount(amount);
--        if (amount == 0) {
-+        if (false && amount == 0) { // Paper - remove CraftItemStack#setAmount null assignment
-             this.handle = null;
-         }
-     }