asset list not updated from (test) network

[dckc]

@rowgraus tried to test governance on emerynet but didn't see ToyUSD. Then he recalled that the list in the UI doesn't reflect the running network:

dapp-econ-gov/src/components/PsmPanel.tsx

Lines 16 to 17 in ec2596c

	// TODO fetch list from RPC
	const anchors = ['AUSD', 'USDC_axl', 'USDC_grv', 'ToyUSD'];

For mainnet, maintaining the list manually might be cost-effective.

But keeping it in sync with whatever testnet the user is working with is another story. And we have some EC testing coming up.