Clear All Favorites

**Is your feature request related to a problem? Please describe.**
As a user, I can add quotes to my favorite list. If I want to delete them, I should delete them one by one.

**Describe the solution you'd like**
Add a "Clear all" functionality in the favorite list. 

**Describe alternatives you've considered**
When the user presses the clear all button, all favorite quotes will be deleted. 

