Refactor related tasks to subtasks

app/locales/taiga/locale-en.json

@@ -33,7 +33,7 @@
         "PLUGINS": "Plugins",
         "ONE_ITEM_LINE": "One item per line...",
         "NEW_BULK": "New bulk insert",
-        "RELATED_TASKS": "Related tasks",
+        "SUBTASKS": "Subtasks",
         "PREVIOUS": "Previous",
         "NEXT": "Next",
         "LOGOUT": "Logout",

app/partials/includes/modules/related-tasks.jade

@@ -3,7 +3,7 @@ section.related-tasks(
     ng-show="showRelatedTasks()"
 )
     .related-tasks-header
-        span.related-tasks-title(translate="COMMON.RELATED_TASKS")
+        span.related-tasks-title(translate="COMMON.SUBTASKS")
         div(tg-related-task-create-button)
     .related-tasks-body(tg-tasks-sortable="reorderTask(task, newIndex)")
         .row.single-related-task.js-related-task(