User Story

As a mapper, I want to be able to answer with "Can't say", so that I can ignore objects in case I am uncertain

This is an idea that was brought up by @tordans in #29.

Acceptance Criterias

When presenting the quest interface, the app also displays "Can't say" as an option
When the mapper taps "Can't say", the quest interface is dismissed
Object-quest combinations for which the mapper has chosen "Can't say" are displayed differently on the map
If the object matches another quest that is not marked as "Can't say", that other quest is displayed when tapping the object
The mapper's "Can't say" choices persist across app restart
The app allows the mapper to reset the "Can't say" choices
- As an MVP, this can be a "Clear all" button