fixup: CLI arguments for C, CPP, Go, Ruby

[rjzak]

C, C++, Go, Ruby receive command line input instead of stdin.

Refs #23

Go has a go.mod to allow it to be built easily with regular Go.

Overall cleanup for consistency.

[rvolosatovs]

Good work, let's make sure all of these are consistent

[rvolosatovs]

The C, C++ and Go examples still incorrectly handle negative numbers:

$ nix build github:rjzak/codex/fix_c_cpp_go_ruby#fibonacci-cpp
$ echo -1 | enarx run ./result/main.wasm                      
Which Fibonacci index to find? Fibonacci sequence number at index -1 is -1
$ nix build github:rjzak/codex/fix_c_cpp_go_ruby#fibonacci-c  
$ echo -1 | enarx run ./result/main.wasm                    
Which Fibonacci index to find? Fibonacci sequence number at index -1 is -1
$ nix build github:rjzak/codex/fix_c_cpp_go_ruby#fibonacci-go
$ echo -1 | enarx run ./result/main.wasm                     
Which Fibonacci index to find? Fibonacci sequence number at index -1 is -1

Meanwhile, Rust and Zig:

$ nix build github:rjzak/codex/fix_c_cpp_go_ruby#fibonacci-rust    
$ echo -1 | enarx run ./result/main.wasm
Enter a non-negative number:
thread 'main' panicked at 'Failed to parse number: ParseIntError { kind: InvalidDigit }', src/main.rs:23:38
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: KVM error: Shutdown
$ nix build github:rjzak/codex/fix_c_cpp_go_ruby#fibonacci-zig 
$ echo -1 | enarx run ./result/main.wasm                     
No arguments specified, please specify Fibonacci sequence index: 
error: InvalidCharacter
Error: failed to execute default function

Caused by:
    Exited with i32 exit status 1
    wasm backtrace:
        0: 0x35ae - <unknown>!<wasm function 17>

[rvolosatovs]

As discussed offline, approving to unblock this and the rest will be fixed in a follow-up!