[Tarantool-patches] [PATCH 2.X 1/7] module api: export box_tuple_validate

[Alexander Turenko]

> Part of #5273

Sorry for nitpicking, but the issue states 'expose everything that is
needed for external key_def module'. The commit technically is not part
of the issue.

Either change the issue, or link commits with
tarantool/vshard-cluster-api#5, or file a separate issue (I would do the
latter).

It is just to don't mix different things into one: #5273 have certain
definition of done. It will be hard to understand what going on in the
future if we'll mix everything together.

(It is the same for all commits.)