Message/Handler: Rely on PacketContext-provided World instance

1.16 completely overhauled how Dimension and DimensionType work.
Just remove the DimensionType serialization for now and provide the
associated World instance directly from Fabric's PacketContext.

src/main/java/li/cil/tis3d/common/network/handler/AbstractMessageHandler.java

@@ -28,45 +28,6 @@ public void onMessage(final T message, final PacketContext context) {
 
     @Nullable
     protected World getWorld(final DimensionType dimension, final PacketContext context) {
-        switch (context.getPacketEnvironment()) {
-            case CLIENT:
-                //noinspection MethodCallSideOnly Guarded by CLIENT switch case.
-                return getWorldClient(dimension, context);
-            case SERVER:
-                return getWorldServer(dimension, context);
-            default:
-                return null;
-        }
-    }
-
-    @Environment(EnvType.CLIENT)
-    @Nullable
-    private static World getWorldClient(final DimensionType dimension, final PacketContext context) {
-        final PlayerEntity player = context.getPlayer();
-        if (player == null) {
-            return null;
-        }
-
-        final World world = player.world;
-        if (world == null) {
-            return null;
-        }
-
-        //~ if (world.getDimension().getType() != dimension) {
-            //~ return null;
-        //~ }
-
-        return world;
-    }
-
-    @Nullable
-    private static World getWorldServer(final DimensionType dimension, final PacketContext context) {
-        final MinecraftServer server = context.getPlayer().getServer();
-        if (server == null) {
-            return null;
-        }
-
-        //~ return server.getWorld(dimension);
-        return null; // XXX
+        return context.getPlayer().world;
     }
 }

src/main/java/li/cil/tis3d/common/network/handler/AbstractMessageHandlerWithDimension.java

@@ -9,6 +9,6 @@
 public abstract class AbstractMessageHandlerWithDimension<T extends AbstractMessageWithDimension> extends AbstractMessageHandler<T> {
     @Nullable
     protected World getWorld(final T message, final PacketContext context) {
-        return getWorld(message.getDimension(), context);
+        return context.getPlayer().world;
     }
 }

src/main/java/li/cil/tis3d/common/network/message/AbstractMessageWithDimension.java

@@ -6,33 +6,21 @@
 import net.minecraft.world.dimension.DimensionType;
 
 public abstract class AbstractMessageWithDimension extends AbstractMessage {
-    private DimensionType dimension;
 
     AbstractMessageWithDimension(final World world) {
-        //~ this.dimension = world.dimension.getType();
     }
 
     AbstractMessageWithDimension() {
     }
 
-    // --------------------------------------------------------------------- //
-
-    public DimensionType getDimension() {
-        return dimension;
-    }
-
     // --------------------------------------------------------------------- //
     // AbstractMessage
 
     @Override
     public void fromBytes(final ByteBuf buf) {
-        final PacketByteBuf buffer = new PacketByteBuf(buf);
-        //~ dimension = DimensionType.byRawId(buffer.readVarInt());
     }
 
     @Override
     public void toBytes(final ByteBuf buf) {
-        final PacketByteBuf buffer = new PacketByteBuf(buf);
-        //~ buffer.writeVarInt(dimension.getRawId());
     }
 }