Added PlayerToggleSprint event and sprinting related API.

By: Rigby <rigby@onarandombox.com>

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java

@@ -298,6 +298,14 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         return getHandle().isSneaking();
     }
 
+    public boolean isSprinting() {
+        return getHandle().at();
+    }
+
+    public void setSprinting(boolean sprinting) {
+        getHandle().g(sprinting);
+    }
+
     public void loadData() {
         server.getHandle().playerFileData.b(getHandle());
     }