JS: add query js/unused-property

javascript/ql/src/Declarations/UnusedVariable.ql

@@ -10,23 +10,7 @@
  */
 
 import javascript
-
-/**
- * A local variable that is neither used nor exported, and is not a parameter
- * or a function name.
- */
-class UnusedLocal extends LocalVariable {
-  UnusedLocal() {
-    not exists(getAnAccess()) and
-    not exists(Parameter p | this = p.getAVariable()) and
-    not exists(FunctionExpr fe | this = fe.getVariable()) and
-    not exists(ClassExpr ce | this = ce.getVariable()) and
-    not exists(ExportDeclaration ed | ed.exportsAs(this, _)) and
-    not exists(LocalVarTypeAccess type | type.getVariable() = this) and
-    // common convention: variables with leading underscore are intentionally unused
-    getName().charAt(0) != "_"
-  }
-}
+import UnusedVariable
 
 /**
  * Holds if `v` is mentioned in a JSDoc comment in the same file, and that file