do not write chainInfo to vstorage in testing environments

[0xpatrickdev]

What

Testing environments publish agoricNames.chainConnection and agoricNames.chain by way of write-chain-info.js. This was to facilitate early chainHub designs where consumers could provide their own chain info or fallback to agoricNames for a lookup.

Since we've yet to run write-chain-info.js on mainnet, and may not have plans to (see #10602), we should remove this configuration.

Why

So testing environments resemble mainnet and code isn't accidentally reliant on an API that's not in mainnet.

How

1. prefer decentral-itest-orchestration-config.json to packages/vm-config/decentral-itest-orchestration-chains-config.json (no write-chain-info.js)
2. ensure test/example contracts that currently depend on lookupChainInfo in ChainHub pre-register their own chain info
3. do not call override-chain-info in multichain-testing