Created @Interpolate annotation for Interpolators to know which fields to interpolate (instead of all public fields)

src/main/java/eu/crushedpixel/replaymod/holders/Position.java

@@ -1,5 +1,6 @@
 package eu.crushedpixel.replaymod.holders;
 
+import eu.crushedpixel.replaymod.interpolation.Interpolate;
 import eu.crushedpixel.replaymod.interpolation.KeyframeValue;
 import lombok.AllArgsConstructor;
 import lombok.Data;
@@ -14,7 +15,9 @@ import net.minecraft.entity.Entity;
 @EqualsAndHashCode(callSuper=true)
 public class Position extends KeyframeValue {
 
+    @Interpolate
     public double x, y, z;
+    @Interpolate
     public double pitch, yaw, roll;
 
     private Integer spectatedEntityID;