Update copyright date and "SIL International→Global"

[merchako]

No description provided.

[lyonsil]

Why just this one file? There are 111 matches of "SIL International" is the *.cs files from what I see at grep -r --include="*.cs" "SIL International" | wc -l.

[imnasnainaec]

A search for "international" in this repo (https://github.com/search?q=repo%3Asillsdev%2Ficu-dotnet+International&type=code) shows many other copyright statements that also need to be updated.

[merchako]

Yeah, maybe we just leave it then. I was just passing by and saw the need to change. Trying to get more comfortable making commits and PRs.

[tombogle]

We can probably just add to this PR for all the additional places. I had started working on a similar change a few weeks ago in some other repos, but reigned it in as it was still unclear whether we were supposed to use "SIL Global" or the new (as yet undecided/unannounced) name for the "SCO" that will represent what was formerly sometimes called "International" (i.e., the part of SIL International that was not associated with a particular part of the world). Now it's clear that we should use SIL Global.