box: account for all tuple format field definitions in `cmp` and `hash`

Previously, reusable tuple formats were only used for ephemeral spaces and
by `net.box` (which only used 'name' definitions), so non-space tuple
format definitions were ignored in tuple format comparison and hash
functions, but in scope of #4693 reusable tuple formats will be
interchangeable with space formats, so now we need to account for these
too.

Needed for #4693

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