Use MONO_ENV_OPTIONS to pass the debug arguments to mono (#66)
Use MONO_ENV_OPTIONS to pass the debug arguments to mono (#66)

This allows passing the arguments to e.g. a mono built from the dotnet/runtime repo since the executable doesn't take the usual mono options.

Example of launch.json:

```
{
            "type": "mono",
            "request": "launch",
            "name": "mono-netcore",
            "program": "/Users/thaysgrazia/runtime/artifacts/bin/MyConsoleApp/Debug/net5.0/MyConsoleApp.dll",
            "runtimeExecutable": "/Users/thaysgrazia/runtime/.dotnet-mono/dotnet"
}
```

Co-authored-by: Alexander Köplinger <a4d3028640b16b8635f2d7ab9cbb07a71466c3cb@outlook.com>
Microsoft/vscode-mono-debug,Microsoft/vscode-mono-debug