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/0801-Fix-text-display-error-on-spawn.patch

@@ -0,0 +1,19 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Nassim Jahnke <nassim@njahnke.dev>
+Date: Thu, 16 Mar 2023 16:27:50 +0100
+Subject: [PATCH] Fix text display error on spawn
+
+
+diff --git a/src/main/java/net/minecraft/world/entity/Display.java b/src/main/java/net/minecraft/world/entity/Display.java
+index bd56721485b3b4ac81c97d60fc2a83bfc20977c0..a658943669cdfd49f66ba713505d11b33306ed86 100644
+--- a/src/main/java/net/minecraft/world/entity/Display.java
++++ b/src/main/java/net/minecraft/world/entity/Display.java
+@@ -892,7 +892,7 @@ public abstract class Display extends Entity {
+             b = loadFlag(b, nbt, "default_background", (byte)4);
+             Optional<Display.TextDisplay.Align> optional = Display.TextDisplay.Align.CODEC
+                 .decode(NbtOps.INSTANCE, nbt.get("alignment"))
+-                .resultOrPartial(Util.prefix("Display entity", Display.LOGGER::error))
++                .result() // Paper - Hide text display error on spawn
+                 .map(Pair::getFirst);
+             if (optional.isPresent()) {
+                 b = switch ((Display.TextDisplay.Align)optional.get()) {