Fix code quality tools configuration and workflow

- Fix PHP CodeSniffer configuration to use WordPress coding standards
- Add WordPress stubs to PHPStan configuration
- Fix Codacy Analysis action by removing unsupported parameter
- Update SonarCloud action to use recommended sonarqube-scan-action
- Add comprehensive documentation for code quality tools
- Update composer scripts to use vendor binaries

phpstan.neon

@@ -14,6 +14,11 @@ parameters:
             - dist (?)
     ignoreErrors:
         - '#Function apply_filters invoked with [0-9]+ parameters, 2 required.#'
+        - '#Function [a-zA-Z0-9_]+ not found.#'
+        - '#Call to static method [a-zA-Z0-9_:()]+ on an unknown class [a-zA-Z0-9_]+.#'
+
+includes:
+    - vendor/szepeviktor/phpstan-wordpress/extension.neon
         - '#Function do_action invoked with [0-9]+ parameters, 1 required.#'
         - '#Function add_action invoked with [0-9]+ parameters, 2 required.#'
         - '#Function add_filter invoked with [0-9]+ parameters, 2 required.#'