Run PMD by default

[newtork]

• Make the code quality related plugins runnable from sub modules.
• Enable PMD by default

Sample output:

mvn clean install -f core

[...]

[INFO] --- pmd:3.25.0:pmd (pmd) @ core ---
[INFO] PMD version: 7.3.0
[INFO] Rendering content with org.apache.maven.skins:maven-fluido-skin:jar:2.0.0-M9 skin
[INFO] 
[INFO] <<< pmd:3.25.0:check (default) < :pmd @ core <<<
[INFO] 
[INFO] 
[INFO] --- pmd:3.25.0:check (default) @ core ---
[WARNING] PMD Failure: com.sap.ai.sdk.core.AiCoreDestination:25 Rule:LocalVariableCouldBeFinal Priority:3 Local variable 'destination' could be declared final.
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  21.686 s
[INFO] Finished at: 2024-10-18T12:45:48+02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-pmd-plugin:3.25.0:check (default) on project core: PMD 7.3.0 has found 1 violation. For more details see: C:\SAPDevelop\ai-sdk-java\core\target\pmd.xml -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

[MatKuhr]

LGTM

However, the GH pipeline will now run the PMD check twice. Also, the other plugins (checkstyle, maybe more?) still won't run locally.

WDY think, should we make it consistent? Or was there a specific reason to only change it for PMD?