That may be the only question you have.
Did the UN issue any resolution against imposing and enforcing a No-Fly Zone?
The question should be, by what mechanism is the prinicples of the Charter binding on the U.S., and its citizens, and what are the means of enforcement. And, I think I've answered that.
Yes you did.
It is not as if the U.N. would, or could, sanction the U.S. for violating Iraqi airspace, but those people who do (in violation of the treaty) then loose some of it's protections as alternate guidlines, such as Geneva, are applied to them - for they've become something different that peace loving, non-combatant states.
I guess that's the choice we made then.
Answered or not your entire argument is semantic because IOWs both the U.S. and Iraq had lost their standing with the UN. Iraq was certainly the first to violate their UN Charter obligations when they attacked Kuwait unprovoked.