Language of email notification about creating Q&A topic should correspond to the chosen language of the subscribed user

Pre-condition:
1. At least two users should be created and logged
2. Both of users should have VIEW_TOPICS and CREATE_POST permissions. User 2 should also have CREATE_QUESTIONS
3. At least one branches created
4. User1 should be subscribed on branch
5. Current language of User1 is English

Check out a correctness of email notification in different languages:
1. English - There is new topic in your favourite forum.
2. Russian - На Вашем любимом форуме появилась новая тема.
3. Ukrainian - На вашому улюбленому форумі з'явилася нова тема.