STD: Recreate OS dependant handlers.

[TheNachoBIT]

Its mostly easy to implement, although it needs this enhancement first to make it possible: https://github.com/nucleus-lang/nucleus/issues/5

The idea is to have a global struct called STDHandler that can act as a platform-agnostic data handler.

In there you will be able to see all of the parameters you need for each OS that this programming language will support.

Although making it 100% independant from OS stuff is hard on Windows because all of the handlers are API-dependant instead of running through a file system like Linux does. So for Windows you gotta need a C++ include from Windows.h

But despite all of this, we can make it independant from C++'s STD and use whatever API the OS currently has.

struct STDHandler
{
    # Windows.
    var WindowsHND: int = -11;

    # Linux
    var LinuxHND: string = "path/to/stdout/file";
};

[TheNachoBIT]

Issue https://github.com/nucleus-lang/nucleus/issues/5 and https://github.com/nucleus-lang/nucleus/issues/6 are now done!

Although one thing i forgot it needed is missing, and its the ability to include files from other programming languages inside Nucleus without the need of Clang externally or through a C++ file: https://github.com/nucleus-lang/nucleus/issues/12