PreSpawnerSpawnEvent

This adds a separate event before an entity is spawned by a spawner
which contains the location of the spawner too similarly to how the
SpawnerSpawnEvent gets called instead of the CreatureSpawnEvent for
spawners.

paper-server/patches/sources/net/minecraft/world/level/BaseSpawner.java.patch

@@ -47,10 +47,10 @@
 +                            continue;
 +                        }
 +                        // Paper start - PreCreatureSpawnEvent
-+                        com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent event = new com.destroystokyo.paper.event.entity.PreCreatureSpawnEvent(
++                        com.destroystokyo.paper.event.entity.PreSpawnerSpawnEvent event = new com.destroystokyo.paper.event.entity.PreSpawnerSpawnEvent(
 +                            io.papermc.paper.util.MCUtil.toLocation(world, d0, d1, d2),
 +                            org.bukkit.craftbukkit.entity.CraftEntityType.minecraftToBukkit(optional.get()),
-+                            org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.SPAWNER
++                            io.papermc.paper.util.MCUtil.toLocation(world, pos)
 +                        );
 +                        if (!event.callEvent()) {
 +                            flag = true;