Should herald support --chain argument, or should the chain (aka env.coin) be inferred from DBState?

[moodyjon]

In most cases the DB (--db_dir=X) will have been populated by scribe, and so it's the scribe --chain=Y argument that's determinative.

(venv) swdev1@Jonathans-Mac-mini hub % herald --help
usage: herald [-h] --db_dir DB_DIR [--reorg_limit REORG_LIMIT] [--chain {mainnet,regtest,testnet}] [--max_query_workers MAX_QUERY_WORKERS] [--cache_all_tx_hashes] [--cache_all_claim_txos]
..snip...
optional arguments:
  -h, --help            show this help message and exit
  --db_dir DB_DIR       Path of the directory containing lbry-rocksdb.
  --reorg_limit REORG_LIMIT
                        Max reorg depth
  --chain {mainnet,regtest,testnet}
                        Which chain to use, default is mainnet, others are used for testing
...snip...