Rename baby zombie movement config option

This option does not set the absolute speed of the entity as the name
implies. It sets a modifier. The default (vanilla) value of `0.5` sets
the baby zombie to move at 50% faster than the base speed.

A negative value like `-0.4` would set them to move at 40% slower.

There should be no functional changes as a result of this change, it's
just clarifying the config name.

Spigot-Server-Patches/Configurable-Disabling-Cat-Chest-Detection.patch

@@ -6,7 +6,7 @@ Subject: [PATCH] Configurable Disabling Cat Chest Detection
 Offers a gameplay feature to stop cats from blocking chests
 
 diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
-index d663b15ceb..2782970393 100644
+index 6c775986d..e80ffe34a 100644
 --- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 +++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
 @@ -0,0 +0,0 @@ public class PaperWorldConfig {
@@ -20,7 +20,7 @@ index d663b15ceb..2782970393 100644
 +    }
  }
 diff --git a/src/main/java/net/minecraft/server/BlockChest.java b/src/main/java/net/minecraft/server/BlockChest.java
-index 00b11a4b20..5fd6061f60 100644
+index 7bde15861..65b616481 100644
 --- a/src/main/java/net/minecraft/server/BlockChest.java
 +++ b/src/main/java/net/minecraft/server/BlockChest.java
 @@ -0,0 +0,0 @@ public class BlockChest extends BlockTileEntity implements IBlockWaterlogged {