If a single op is larger than consensus_max_batch_size_bytes, consensus gets stuck

I noticed on a cluster test that a leader was spinning with log messages like:

I0829 14:17:31.870786 22184 log_cache.cc:307] T e7cacfdb22744496a6d5d66227a69823 P 5d15962d2f2445b1ba15b93ead4fb31b: Successfully read 1 ops from disk (866604..866604)
I0829 14:17:31.873234 6186 log_cache.cc:307] T e7cacfdb22744496a6d5d66227a69823 P 5d15962d2f2445b1ba15b93ead4fb31b: Successfully read 1 ops from disk (866604..866604)
I0829 14:17:31.875713 22184 log_cache.cc:307] T e7cacfdb22744496a6d5d66227a69823 P 5d15962d2f2445b1ba15b93ead4fb31b: Successfully read 1 ops from disk (866604..866604)
I0829 14:17:31.878078 6186 log_cache.cc:307] T e7cacfdb22744496a6d5d66227a69823 P 5d15962d2f2445b1ba15b93ead4fb31b: Successfully read 1 ops from disk (866604..866604)

After investigation, it seems this op was larger than 1MB (default consensus batch size) and this caused this tight loop behavior with no progress.