Add xcb_icccm_wm_hints_t attributes

[RFCreate]

Add missing xcb_icccm_wm_hints_t *hints pointer and the attribute hints->flags from the wlroots C source code to this repo.

EDIT: This is incomplete, please read next comment.

[RFCreate]

Finally found all attributes of the xcb_icccm_wm_hints_t struct. Now added to this PR alongside with the Hints class with all the properties.

[flacjacket]

Thanks!

[RFCreate]

@flacjacket what is the xcbcommon error?

[flacjacket]

@RFCreate That looks like we are just trying to use the wrong python-xkbcommon version when packaging, there were some changes there that means we need to be careful with the version that we pick. I can look into that since it happens on master, and it ultimately doesn't fail in the CI build (since our docker container has a different xkbcommon that is compatible), so this change should be fine.

[heuer]

I guess it's the same problem as for #211.

I believe @jwijenbergh fixed the problem in his 0.18 branch but I cannot find the commit. I believe he fixed the xkbcommon version to a specific version, but I am not sure.

[RFCreate]

Could this suggestion qtile/qtile#4946 work?

pip3 install 'xkbcommon<1.1'

[RFCreate]

Fixed in #223

@flacjacket @heuer