a class that helps you manage the state of a bit. It has a generic
type L that represents the loading state of the bit. You can use
MsgBitControl if you want to use a string as the loading state.
defines a simple BitControl. This allows you to manage global state.
Provide a worker function that will be called when the bit is first
accessed. The worker function should return a FutureOr<V>. The V
type is the type of the data that the bit will hold. The Bit will automatically
also have a loading state and an error state.