box: support tuple formats in IPROTO responses

Tuple formats are sent in a separate IPROTO_TUPLE_FORMATS response body
field, which is namely a mapping from format identifiers to serialized
tuple formats.

The algorithm for parsing IPROTO response body is the following:
1. Parse tuple formats and build a tuple format index.
2. Parse data passing the tuple format index in the decoding context.

Add new backward compatibility option `box_tuple_extension` which controls
the server's `IPROTO_FEATURE_CALL_RET_TUPLE_EXTENSION` bit: needed for
users that don't expect the new tuple extension to be returned in call and
eval responses instead of basic MsgPack types. This option will
also be used for `IPROTO_FEATURE_CALL_ARG_TUPLE_EXTENSION` bit with the
same purpose.

Closes #8147

NO_DOC=<added in a later commit together with documentation of tuple
        formats in IPROTO `call` and `eval` arguments>