box: introduce space type

Introduces a new field `type` to the space definition. Currently it can
only be "normal" or "data-temporary". It is backwards compatible with
temporary=true.

@TarantoolBot document
Title: Introduce space field type

A new space definition field "type" can now be used to specify the type
of the space. Usage: box.schema.create_space("s", { type = "normal" }).
Currently only 2 types are supported: "normal" & "data-temporary", which
is equivalent to { temporary = true }. Old-style { temporary = true } is
still supported, but only one option either 'temporary' or 'type' may be
specified at the same time.

Space type "temporary" will be introduced in a later commit.
In the future options "local", "synchronous", etc. may also be
supported.

NO_TEST=will be tested in the following commit