Remove wall-time / unused skip tick protection (#11412)

Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.

patches/server/0738-Added-byte-array-serialization-deserialization-for-P.patch

@@ -0,0 +1,39 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Nex <nex@bits.team>
+Date: Thu, 24 Feb 2022 16:28:07 +0100
+Subject: [PATCH] Added byte array serialization/deserialization for
+ PersistentDataContainers
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
+index 984e988a47aa55a3fd92198e379d0f92f511daef..5a4e7e7150b7c137b077e0b393f17ed35b5aec34 100644
+--- a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
++++ b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
+@@ -184,4 +184,27 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
+         this.customDataTags.clear();
+     }
+     // Paper end
++
++    // Paper start - byte array serialization
++    @Override
++    public byte[] serializeToBytes() throws java.io.IOException {
++        final net.minecraft.nbt.CompoundTag root = this.toTagCompound();
++        final java.io.ByteArrayOutputStream byteArrayOutput = new java.io.ByteArrayOutputStream();
++        try (final java.io.DataOutputStream dataOutput = new java.io.DataOutputStream(byteArrayOutput)) {
++            net.minecraft.nbt.NbtIo.write(root, dataOutput);
++            return byteArrayOutput.toByteArray();
++        }
++    }
++
++    @Override
++    public void readFromBytes(final byte[] bytes, final boolean clear) throws java.io.IOException {
++        if (clear) {
++            this.clear();
++        }
++        try (final java.io.DataInputStream dataInput = new java.io.DataInputStream(new java.io.ByteArrayInputStream(bytes))) {
++            final net.minecraft.nbt.CompoundTag compound = net.minecraft.nbt.NbtIo.read(dataInput);
++            this.putAll(compound);
++        }
++    }
++    // Paper end - byte array serialization
+ }