task: Add Composite Entity pattern (#1705)

* add composite entity pattern

* add composite entity pattern

* Update ReactorTest.java

* resolve some code quality problems

* modified a lot

* remove some extra codes

* modified README

* removed the author name and adjusted the spacing

Co-authored-by: zwebrain <11811721@mail.sustech.edu.cn>
Co-authored-by: Subhrodip Mohanta <hello@subho.xyz>

composite-entity/src/main/java/com/iluwatar/compositeentity/CompositeEntity.java

@@ -0,0 +1,23 @@
+package com.iluwatar.compositeentity;
+
+/**
+ * Composite entity is the coarse-grained entity bean which may be the coarse-grained object, or may
+ * contain a reference to the coarse-grained object.
+ */
+
+public class CompositeEntity {
+
+  private final ConsoleCoarseGrainedObject console = new ConsoleCoarseGrainedObject();
+
+  public void setData(String message, String signal) {
+    console.setData(message, signal);
+  }
+
+  public String[] getData() {
+    return console.getData();
+  }
+
+  public void init() {
+    console.init();
+  }
+}