std.os.uefi.protocol: ziggify function signatures

[dotcarmen]

A lot of the function signatures in std.os.uefi.protocol aren't very ziggy. This PR modifies a significant number of the namespace's functions to align more with verbose Zig code.

• Some parameters changed from * to *const and vice-versa as appropriate
• Some pairs of parameters that represent slices were consolidated into a single slice parameter
• Status errors associated with each function according to the UEFI Specification are handled specifically, resulting in narrow error unions being returned from each function
  • unexpected status codes result in a new call to uefi.unexpectedError, which is akin to posix.unexpectedError
• As appropriate, return values from various functions are returned directly when the underlying function's return value is .success, rather than requiring an output pointer parameter

note: most of std.os.uefi is untested, and that's not really changing here. I'm mostly focused on making sure there are no compiler errors. Any further problems will require a future PR to address.

[dotcarmen]

one problem I'm struggling to address in this PR is the potential for the underlying API to return status codes - most of std.os.uefi already assumes non-.success return values are errors, but I wonder if warnings (high bit clear) should be stored somewhere?