open() should accept "rb" attributes

[l0ud]

Hi. I have a code that is using native paths and antifactory paths to read files in binary mode. I'm struggling with open() limitation to have only "r" mode supported, not "rb".
As far as I see, files are opened in binary mode anyway (when reading line-by-line I'm seeing bytes instead of strings).
This makes code awkward, as I need to specify "rb" to native paths and "r" to artifactory paths, even they are all binary.
Can open function not throw an error when passing "rb" instead of "r" parameter?

[daveswork]

PR created, #484