[Introspection] Enum declarations are moved to the end of the schema file after db pull

It seems models' original declaration order is preserved, but enums are moved to the end of the file. Also, triple-slash comments above enum is lost.

Before:

```zmodel
///
/// Enum for user's role in a space
///
enum SpaceUserRole {
    USER
    ADMIN
}

model Space {
...
}
```

After:

```zmodel
model Space { ... }
...

enum SpaceUserRole {
    USER
    ADMIN
}
```

@svetch for your awareness