add `auto` file detection for sandbox environment default

[cs-shadowbq]

Is your feature request related to a problem? Please describe. file type detection ( Content type detection using magic numbers ) for sandbox environment determination

Describe the solution you'd like add auto file detection for sandbox environment default, incorporate a switch

Describe alternatives you've considered default compiled targets to use the same environment "linux compile target defaults to linux sandbox" etc..

Additional context https://github.com/gabriel-vasile/mimetype

example use of mimetype:

func GetExtensionAndContentType(file io.Reader) (string, string, error) {
    var extension string
    var contentType string
    mimeType, err := mimetype.DetectReader(file)

    if err != nil {
        return "", "", err
    } else {
        extension = mimeType.Extension()
        contentType = mimeType.String()
    }
    return extension, contentType, nil
}

[shadowbq]

Second option

https://github.com/h2non/filetype

[shadowbq]

Additionally use mime types to add data filters.

Usecase: only submit binary files not document files because of possible data leakage or compliance requirements.