Refactor resource configuration:

- Introduce new resource_filter plugin (mandatory hard_default, auto entity_name fallback)
- Replace get_app_conf calls with resource_filter in resource.yml.j2
- Add WEBSERVER_CPUS_EFFECTIVE, WEBSERVER_WORKER_PROCESSES, WEBSERVER_WORKER_CONNECTIONS to 05_webserver.yml
- Update Nginx templates (sys-svc-webserver, web-app-magento, web-app-nextcloud) to use new vars
- Extend svc-prx-openresty config with cpus/mem limits
- Add unit tests for resource_filter

Details: https://chatgpt.com/share/68d3a493-9a5c-800f-8cd2-bd2e7a3e3fda

roles/web-app-magento/templates/nginx.conf.j2

@@ -1,6 +1,6 @@
-worker_processes auto;
+worker_processes {{ WEBSERVER_WORKER_PROCESSES }};
 
-events { worker_connections 1024; }
+events { worker_connections {{ WEBSERVER_WORKER_CONNECTIONS }}; }
 
 http {
   include       /etc/nginx/mime.types;