feature: Implement Serialized Entity Pattern (#2150)

* Add files:
- App.java
- Country.java
- CountryDao.java
- CountrySchemaSql.java
- CountryTest.java
- README.md
- serialize-entity.urm.puml
- pom.xml (inherit from parent pom.xml)
Update files:
- pom.xml (parent pom.xml, add 1 module called serialized-entity)

* Fix duplicated error in pom.xml

* Update:
- pom.xml (module servant, changed by error, now fixed)
- pom.xml (module serialized-entity)

* Update:
- pom.xml (changed, artifactId)

* Update:
- pom.xml

Add:
AppTest.java

* Resolved changes required by the reviewer

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

serialized-entity/src/main/java/com/iluwatar/serializedentity/Country.java

@@ -0,0 +1,47 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.serializedentity;
+import java.io.Serializable;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
+
+/**
+ * A Country POJO taht represents the data that will serialize and store in database.
+ */
+@Getter
+@Setter
+@EqualsAndHashCode
+@ToString
+@AllArgsConstructor
+public class Country implements Serializable {
+
+  private int code;
+  private String name;
+  private String continents;
+  private String language;
+  public static final long serialVersionUID = 7149851;
+
+}