* Break update code out of sstore
* add license disclaimers
* missed one
* add another
* fix regression in openai updates, remove unnecessary functions
* another copyright
* update casts
* fix issue with variadic updates
* remove logs
* remove log
* remove unnecessary log
* save work
* moved a bunch of stuff to scbus
* make modelupdate an object
* fix new screen not updating active screen
* add comment
* make updates into packet types
* different cast
* update comments, remove unused methods
* add one more comment
* add an IsEmpty() on model updates to prevent sending empty updates to client
This PR changes ModelUpdate mechanism from a statically-typed struct to an interface, allowing us to define the update mechanism and the update types separately. This sets us up to move app logic and update mechanisms into separate packages. Ultimately, sstore will only define low-level persistence logic.
