* Easier payment testing
* WIP, more TODOs and some cleanup. Help is appreciated.
* Added dummy button to expire monitoring (doesn't work yet)
* Added TODO
* Make fake tab default if present
* Split controller and change wording from fake to testing
* Extract and simplify checkout testing UI
* Restrict testing access to regtest
Co-authored-by: Dennis Reimann <mail@dennisreimann.de>
