Grammar refactoring

* Grammar refactoring WIP

* ISerializer.grammar

* Fixing various bugs in the grammar

* Small touch that improoves performance

* Fix unknown values grammar

* Various fixes

* Serialization refactoring to drop suboject logic

* Details fixed

* Entity attributes initialization refactoring

* JSDoc error fixed

* Rename value key to default

* Remove useless default

* Revert string keys

js/entity/Vector2DEntity.js

@@ -4,11 +4,11 @@ export default class Vector2DEntity extends IEntity {
 
     static attributes = {
         X: {
-            value: 0,
+            default: 0,
             expected: true,
         },
         Y: {
-            value: 0,
+            default: 0,
             expected: true,
         },
     }