feat(jenkins): add Jenkins CI/CD Platform Cloudron package

- Complete Jenkins package with Java 17 and WAR file download
- Proper CloudronManifest.json with correct metadata
- Custom start.sh script with Jenkins configuration
- Health check endpoint configured for /login
- Follows KNELCloudron- naming convention
- Added comprehensive packaging shortlist with 56 applications prioritized by phase

CloudronPackages/Jenkins/config.yaml

@@ -0,0 +1,11 @@
+# Example configuration template for Jenkins CI/CD
+server:
+  port: 8080
+
+data:
+  dir: /app/data
+
+database:
+  # url: ${CLOUDRON_POSTGRESQL_URL}
+  # redis: ${CLOUDRON_REDIS_URL}
+