Flutter dashboard app performance improvements

The implementation of receiving signals from KUKSA.val using the Riverpod state management library in the Flutter dashboard and cluster dashboard apps is problematic as the signals are being combined in one state object, which is contrary to recommended best practices.  The downside is that any received signal will result in an almost full rebuild of the widget tree and potentially a lot more rendering & repainting than is necessary.  The signals need to be split into their own providers and wired up to the appropriate widgets that require them.