Feature: User challenges

- Option for users to create challenge transactions
- Handle cases gracefully for already challenged and failed transactions
- Maybe a simple modal for now would be enough

Designs
https://gallery.io/projects/MCHbtQVoQ2HCZe9U2R-hJAvE/files/MCEJu8Y2hyDScaPno0VbgyEEZmDHI_TCMAs