Add a G-Machine interpreter for debugging

[Ailrun]

Is your feature request related to a problem? Please describe.
It is really hard to debug G-Machine transpiler with the current setting.

Describe the solution you'd like
Implement a G-Machine interpreter.

Additional context
See https://github.com/Ailrun/core-lang-haskell for a reference.

[Ailrun]

Dev note
Use Maybe Instruction as a return type of the monad.

[Ailrun]

Dev note
Add InterpreterStepMonad
(For undo function)

[Ailrun]

Dev note
Possible commands for CUI

• help
• run
• step
• undo (I believe that last two command should have the names related with each other in some manner. It's not the case for the listed names, so I wonder what are better name for them.)
• break (both adding and removing break commands are included)
• show (a command to display current state)
• etc.

[Ailrun]

Dev note
Current GMachineMonadT is completely broken. Or rather, interpretProgram is broken.
It's impossible to implement checkInterpreterFinished.

[Ailrun]

Dev note
Rename checkInterpreterFinished and others to use GMachine instead of Interpreter.

[Ailrun]

Dev note
Specification for Unwind instruction is broken. Fix it.
(Especially for CAF)