Preparing for the MultiPlatform Overlords

One of my favorite pass times is messing around with this app, by bringing whatever I learn from work into this codebase, to see if I can make this code easier to reason about and maintain. This release is no exception. We've now moved from Moshi -> KotlinX Serialization, and from LiveData to Kotlin StateFlows, and from SharedPreferences to DataStore. The writing is on the wall, a KMP push might happen any year now 😜 The architecture and code separation also makes a bit more sense now, so there is less logic consolidated in the ViewModel, and stuff has been pushed into the repositories. I still feel uncomfortable about the way it's written right now, so there is probably more work to be done on that front.

For user facing changes, landscape mode now looks much cuter, and Fahrenheit toggle should be better 😄