Optimize Network Manager to not need synchronization

Removes synchronization from sending packets
Makes normal packet sends no longer need to be wrapped and queued like it use to work.
Adds more packet queue immunities on top of keep alive to let the following scenarios go out
without delay:
  - Keep Alive
  - Chat
  - Kick
  - All of the packets during the Player Joined World event

Hoping that latter one helps join timeout issues more too for slow connections.

Removes processing packet queue off of main thread
  - for the few cases where it is allowed, order is not necessary nor
    should it even be happening concurrently in first place (handshaking/login/status)

Ensures packets sent asynchronously are dispatched on main thread

This helps ensure safety for ProtocolLib as packet listeners
are commonly accessing world state. This will allow you to schedule
a packet to be sent async, but itll be dispatched sync for packet
listeners to process.

This should solve some deadlock risks

This may provide a decent performance improvement because thread synchronization incurs a cache reset
so by avoiding ever entering a synchronized block, we get to avoid that, and packet sending is a really
hot activity.

Spigot-Server-Patches/Optimize-isOutsideRange-to-use-distance-maps.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Optimize isOutsideRange to use distance maps
 Use a distance map to find the players in range quickly
 
 diff --git a/src/main/java/net/minecraft/server/ChunkMapDistance.java b/src/main/java/net/minecraft/server/ChunkMapDistance.java
-index 279c7a85fb..7cd4e29123 100644
+index 279c7a85fb5..7cd4e291235 100644
 --- a/src/main/java/net/minecraft/server/ChunkMapDistance.java
 +++ b/src/main/java/net/minecraft/server/ChunkMapDistance.java
 @@ -0,0 +0,0 @@ public abstract class ChunkMapDistance {
@@ -77,7 +77,7 @@ index 279c7a85fb..7cd4e29123 100644
  
      public String c() {
 diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
-index 78a8a3cc68..e2abda1bc3 100644
+index 78a8a3cc68f..e2abda1bc37 100644
 --- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
 +++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
 @@ -0,0 +0,0 @@ public class ChunkProviderServer extends IChunkProvider {
@@ -148,7 +148,7 @@ index 78a8a3cc68..e2abda1bc3 100644
                              this.world.timings.mobSpawn.startTiming(); // Spigot
                              EnumCreatureType[] aenumcreaturetype1 = aenumcreaturetype;
 diff --git a/src/main/java/net/minecraft/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
-index 48bbaec4b6..6e8179b465 100644
+index 48bbaec4b64..6e8179b4651 100644
 --- a/src/main/java/net/minecraft/server/EntityPlayer.java
 +++ b/src/main/java/net/minecraft/server/EntityPlayer.java
 @@ -0,0 +0,0 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
@@ -161,7 +161,7 @@ index 48bbaec4b6..6e8179b465 100644
          super((World) worldserver, gameprofile);
          playerinteractmanager.player = this;
 diff --git a/src/main/java/net/minecraft/server/PlayerChunk.java b/src/main/java/net/minecraft/server/PlayerChunk.java
-index 568fbbd5f2..8742d13499 100644
+index 4b341c81fc9..bae9371a1e2 100644
 --- a/src/main/java/net/minecraft/server/PlayerChunk.java
 +++ b/src/main/java/net/minecraft/server/PlayerChunk.java
 @@ -0,0 +0,0 @@ public class PlayerChunk {
@@ -192,7 +192,7 @@ index 568fbbd5f2..8742d13499 100644
  
      // Paper start
 diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
-index a780cf5b45..099e612171 100644
+index d460bc62b8d..4317d9b98e4 100644
 --- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
 +++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
 @@ -0,0 +0,0 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {