Switch to using ForgeFlower for Paper Only mc-dev imports

ForgeFlower is better than Spigots FernFlower at decompiling the source.

However, in order to maintain the CraftBukkit patches, we must keep
using spigots for the primary.

However, for any file that we import on top of Spigots imported files
there is nothing stopping us from using better decompiled files.

So these changes will use ForgeFlower to maintain a better set of
decomped files, so anything we add on top of Paper can start off
in a better spot.

Spigot-Server-Patches/Ability-to-apply-mending-to-XP-API.patch

@@ -10,7 +10,7 @@ of giving the player experience points.
 Both an API To standalone mend, and apply mending logic to .giveExp has been added.
 
 diff --git a/src/main/java/net/minecraft/server/EnchantmentManager.java b/src/main/java/net/minecraft/server/EnchantmentManager.java
-index c90e413f8c..c365bfea04 100644
+index fd6df39f17..f03aef2fed 100644
 --- a/src/main/java/net/minecraft/server/EnchantmentManager.java
 +++ b/src/main/java/net/minecraft/server/EnchantmentManager.java
 @@ -0,0 +0,0 @@ public class EnchantmentManager {
@@ -19,10 +19,10 @@ index c90e413f8c..c365bfea04 100644
  
 +    public static ItemStack getRandomEquippedItemWithEnchant(Enchantment enchantment, EntityLiving entityliving) { return b(enchantment, entityliving); } // Paper - OBFHELPER
      public static ItemStack b(Enchantment enchantment, EntityLiving entityliving) {
-         List list = enchantment.a(entityliving);
- 
+         List<ItemStack> list = enchantment.a(entityliving);// Paper - decompile fix
+         if (list.isEmpty()) {
 diff --git a/src/main/java/net/minecraft/server/Enchantments.java b/src/main/java/net/minecraft/server/Enchantments.java
-index 836fe13c3d..27093a672e 100644
+index 8cfb38b826..44b2d428b3 100644
 --- a/src/main/java/net/minecraft/server/Enchantments.java
 +++ b/src/main/java/net/minecraft/server/Enchantments.java
 @@ -0,0 +0,0 @@ public class Enchantments {