AXIS2-6040 Define Automatic-Module-Name for Java 9+ module system

Add Automatic-Module-Name manifest entry to the root POM's
maven-jar-plugin configuration. This applies to all modules and
provides stable module names derived from groupId + artifactId
(e.g., org.apache.axis2.axis2-kernel).

Without this, the Java module system derives unstable module names
from JAR filenames, producing IDE warnings like "Name of automatic
module 'axis2.kernel' is unstable, it is derived from the module's
file name."

This is a passive manifest entry — ignored entirely on the classpath.
Only takes effect for users who explicitly use Java modules (JPMS).

Author: robertlazarski

pom.xml

@@ -1046,6 +1046,16 @@
                 <plugin>
                     <artifactId>maven-jar-plugin</artifactId>
                     <version>3.5.0</version>
+                    <configuration>
+                        <archive>
+                            <manifestEntries>
+                                <!-- AXIS2-6040: Stable module name for Java 9+ module system.
+                                     Without this, the module name is derived from the JAR filename
+                                     and changes with version numbers, producing IDE warnings. -->
+                                <Automatic-Module-Name>${project.groupId}.${project.artifactId}</Automatic-Module-Name>
+                            </manifestEntries>
+                        </archive>
+                    </configuration>
                 </plugin>
                 <plugin>
                     <artifactId>maven-plugin-plugin</artifactId>