Implement Hash of object

We have to calculate the hash according to the type of Object and return a value.
There is currently `M__hash__` but it is not implemented in any Object.
```go
type I__hash__ interface {
M__hash__() (Object, error)
}
```

First, we have to implement `M__hash__` of numbers and strings(int, float, complex, string).
This is also necessary for the implementation of the dictionary.