gpui: Add Global marker trait (#7095)

This should prevent a class of bugs where one queries the wrong type of
global, which results in oddities at runtime.

Release Notes:

- N/A

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Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
e6ebe7974dPiotr Osiewicz committed on 1/30/2024, 7:08:20 PM· committed by GitHubparent7bfa584
60 files changedLine totals unavailable