Questions permissions

As an Owner I'd like to have CREATE_QUESTIONS permission available in Branch Permissions so that I can grant it to groups

Acceptance Criteria

• Plugin questions-n-answers should be created. The overall functionality will be implemented in other tasks, this one is only about permissions. Nothing to be configured in the list of plugins.
• When questions-n-answers plugin is installed and enabled, CREATE_QUESTIONS permission should show up in Branch Permissions of a selected branch. It should not be shown if plugin is disabled.
• If the permission is granted to a group, users in this group should see Ask Question button in the selected branch
• Ask Question, Start Discussion, Create Code Review buttons should be grouped inside of Create Topic button (it should become a combobox button).

Translations:

• Button Title
  • Ask Question
  • Задать Вопрос
  • Задати Питання
• Hint
  • Do you need an answer or explanation?
  • Нужен ответ или пояснение по интересующему вопросу?
  • Шукаэте відповідь або пояснення?