[Serializer] Add Debug command

Author: loic425

serializer.rst

@@ -491,6 +491,45 @@ value:
             $framework->serializer()->nameConverter('serializer.name_converter.camel_case_to_snake_case');
         };
 
+Debugging the Serializer
+------------------------
+
+Use the ``debug:serializer`` command to dump the serializer metadata of a
+given class:
+
+.. code-block:: terminal
+
+    $ php bin/console debug:serializer 'App\Entity\SomeClass'
+
+        App\Entity\SomeClass
+        --------------------
+
+        +----------------+------------------------------------------------------------+
+        | Property       | Options                                                    |
+        +----------------+------------------------------------------------------------+
+        | firstArgument  | [                                                          |
+        |                |   "groups" => [                                            |
+        |                |       "book:read",                                         |
+        |                |       "book:write",                                        |
+        |                |   ]                                                        |
+        |                |   "maxDepth" => 1,                                         |
+        |                |   "serializedName" => "first_argument"                     |
+        |                |   "ignore" => false                                        |
+        |                |   "normalizationContexts" => [],                           |
+        |                |   "denormalizationContexts" => []                          |
+        |                | ]                                                          |
+        | secondArgument | [                                                          |
+        |                |   "groups" => [                                            |
+        |                |       "book:read",                                         |
+        |                |   ]                                                        |
+        |                |   "maxDepth" => null,                                      |
+        |                |   "serializedName" => null                                 |
+        |                |   "ignore" => false                                        |
+        |                |   "normalizationContexts" => [],                           |
+        |                |   "denormalizationContexts" => []                          |
+        |                | ]                                                          |
+        +----------------+------------------------------------------------------------+
+
 Going Further with the Serializer
 ---------------------------------