Feedback popup

**Is your feature request related to a problem? Please describe.**
We know too little about our users' needs and opinions. Add an optionally anonymous feedback popup that would allow users to share their opinions/suggestions straight from the app.

**Describe the solution you'd like**
A popup window that suggests to leave feedback.
We need to determine how often and how many times to open this window. We should also create a sidenav option to leave feedback at will.

**Describe alternatives you've considered**
Silent analytics that show what the users use the island for. But silent analytics have a downside of not showing users' hopes and dreams