[datatest-stable] support --format terse
[datatest-stable] support --format terse

Support the terse format while listing tests, since that's what the test
runner uses.

Closes: #7932

libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,libra/libra,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core