BAEL-5246: pom cleanup (#4620)

* BAEL-5246: round 1 of pom cleanup - upto "jersey" project

* BAEL-5246: Initial pass for pom cleanup - upto spring-cloud

* BAEL-5246: pom cleanup upto testing-modules/junit5

* BAEL-5246: pom cleanup - upto xstream

* BAEL-5246: pom cleanup - last round (before review)

undertow/pom.xml

@@ -1,27 +1,25 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    
     <groupId>com.baeldung.undertow</groupId>
     <artifactId>undertow</artifactId>
     <packaging>jar</packaging>
     <version>1.0-SNAPSHOT</version>
     <name>undertow</name>
     <url>http://maven.apache.org</url>
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>
         <version>1.0.0-SNAPSHOT</version>
     </parent>
-    <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
-    </properties>
 
     <dependencies>
         <dependency>
             <groupId>io.undertow</groupId>
             <artifactId>undertow-servlet</artifactId>
-            <version>1.4.18.Final</version>
+            <version>${undertow-servlet.version}</version>
         </dependency>
     </dependencies>
 
@@ -54,4 +52,8 @@
         </plugins>
     </build>
 
+    <properties>
+        <undertow-servlet.version>1.4.18.Final</undertow-servlet.version>
+    </properties>
+
 </project>