[maint]: Remove unicode chars from codebase (keywords, function names, variables, etc.)

[alichtman]

Ah, gotcha. We should spin off a task for removing those from function names. I don't think we should have any unicode chars in the codebase except for strings we're printing for the user. It makes the code a lot harder to work with

Originally posted by @alichtman in https://github.com/zdharma-continuum/zinit/pull/107#discussion_r756652075

[pschmitt]

Note that this requires to update not only zinit but also all the annexes.