Add share button when viewing photos

Ghost User
2019-08-28T21:36:12+02:00

Closes #104

### Short description
Adds a share button to quickly share a photo.

### Steps to use this feature

1. Go to photo's tab
2. View photo in album
3. Click share button in top right corner

![image](/uploads/f9f6668d9072779a77bed61fe501f423/image.png)
![image](/uploads/f2516caade341c7137ebee16669b7ecc/image.png)