MQE-1676: Add a static-check that ensures action groups do not have unused arguments

Documentation + fixed static checks

Author: soumyau

docs/commands/mftf.md

@@ -468,6 +468,7 @@ Runs all MFTF static-checks on the test codebase that MFTF is currently attached
 #### Existing static checks
 
 * Test Dependency: Checks that test dependencies do not violate Magento module's composer dependencies.
+* Unused Arguments: Checks that action groups do not have unused arguments.
 
 #### Usage
 

src/Magento/FunctionalTestingFramework/StaticCheck/UnusedArgumentsCheck.php

@@ -120,8 +120,8 @@ private function findUnusedArguments($actionGroup)
 
     /**
      * Returns array of all action attribute values in an action group.
-     * @param $actionGroup
-     * @return array
+     * @param ActionGroupObject $actionGroup
+     * @return array $allAttributeValues
      */
     private function getAllActionAttributeValues($actionGroup)
     {