CreatePreimageChannel returns a FileChannel for the preimage oracle in a detached context.

Main executes the client program in a detached context and exits the current process.

RunProgram executes the Program, while attached to an IO based pre-image oracle, to be served by a host.

CustomChainIDIndicator is used to detect when the program should load custom chain configuration.

0,1,2 used for stdin,stdout,stderr.

These local keys are only used for custom chains.