Add protocol 29 ledger-close-meta reference files

LedgerCloseMetaStreamTests reads a reference JSON per protocol version and
REQUIRE(inJson) fails when one is absent. Coverage stopped at 28; a vnext
build now runs at 29, so the four protocol-29 variants were missing.

Generated with GENERATE_TEST_LEDGER_CLOSE_META=1 for --version 29 only, as
the test's own comment directs, so no existing version's golden data moves.

Author: sisuresh