Update upstream B/CB/S

--- work/Bukkit
Submodule work/Bukkit 6eac6d70..1ef8b9d9:
  > Add Player#openBook(ItemStack) method

--- work/CraftBukkit
Submodule work/CraftBukkit 17543ecf..649921e5:
  > Add Player#openBook(ItemStack) method
  > SPIGOT-2000: Picking up items to shield slot working inconsistently when inventory is full
  > SPIGOT-5037: Player.openMerchant does not show merchant level
  > SPIGOT-5038: Inventory.getHolder returns null for wandering traders

--- work/Spigot
Submodule work/Spigot baafee91..df0eb250:
  > SPIGOT-5043: Desync if world is changed in PlayerSpawnLocationEvent
  > Rebuild patches

Implementation developer note:
This patch adds a "pre-source" patch system for fixing malformed patches
from upstream directly. This seems to keep happening so it's best we
have some way to deal with them. This system brings those issues into
our domain rather than needing to wait for upstream to fix their
malformed files.

Spigot-Server-Patches/Expose-attack-cooldown-methods-for-Player.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Expose attack cooldown methods for Player
 
 
 diff --git a/src/main/java/net/minecraft/server/EntityHuman.java b/src/main/java/net/minecraft/server/EntityHuman.java
-index e316e2af7d..87c4902f83 100644
+index e316e2af7..87c4902f8 100644
 --- a/src/main/java/net/minecraft/server/EntityHuman.java
 +++ b/src/main/java/net/minecraft/server/EntityHuman.java
 @@ -0,0 +0,0 @@ public abstract class EntityHuman extends EntityLiving {
@@ -27,11 +27,11 @@ index e316e2af7d..87c4902f83 100644
          this.aD = 0;
      }
 diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
-index ba60ece457..0386452a8d 100644
+index a22bb25ff..7e2d4f452 100644
 --- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 +++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 @@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
-         this.resourcePackStatus = status;
+         getInventory().setItemInMainHand(hand);
      }
  
 +    //Paper start