create default rex files with static keys

Oqtane.Client/Modules/Controls/PermissionGrid.razor

@@ -65,7 +65,7 @@
         <tbody>
             <tr>
                 <td class="input-group">
-                    <input type="text" name="Username" class="form-control" placeholder="@Localizer["Enter Username"]" @bind="@_username" />
+                    <input type="text" name="Username" class="form-control" placeholder="@Localizer["Username.Enter"]" @bind="@_username" />
                     <button type="button" class="btn btn-primary" @onclick="AddUser">@Localizer["Add"]</button>
                 </td>
             </tr>
@@ -180,7 +180,7 @@
             }
             catch
             {
-                _message = Localizer["Username Does Not Exist"];
+                _message = Localizer["Message.Username.DontExist"];
             }
         }