Post idea: learning about .NET, ICU, and globalilzation formats

[SeanKilleen]

Based on what became my write-up at dotnet/runtime#77585

Just an examination of a quirk that others might encounter, in the hopes that I can clear up confusion.

Will also make a point to speak to the comment on that thread that we shouldn't be testing that. It's correct in that many cases you won't want to be asserting against that output. But in some cases, like my specific case, it was necessary. Worth adding a note to people if they're considering it though.

[SeanKilleen]

Since it ended up being expected behavior on the framework's side, is already written up in the github issue, and I'm not sure readers would benefit from learning about the journey, I'm going to close this.