* Allow observers to respond to AdminMessage requests
Ground work for CannedMessage getters and setters
* Enable CannedMessage config in apps for InkHUD devices
* Migrate the InkHUD::Events AdminModule observer
Use the new AdminModule_ObserverData struct
* Bare-bones NicheGraphics util to access canned messages
Handles loading and parsing. Handle admin messages for setting and getting.
* Send canned messages via on-screen menu
* Change ThreadedMessageApplet from Observer to Module API
Allows us to intercept locally generated packets ('loopbackOK = true'), to handle outgoing canned messages.
* Fix: crash getting empty canned message string via Client API
* Move file into Utils subdir
* Move an include statement from .cpp to .h
* Limit strncpy size of dest, not source
Wasn't critical in ths specific case, but definitely a mistake.
