Guardian native chain id verification

[evan-gray]

Expected Behavior

The guardian could check that a given watcher is connected to the expected chain by checking the chain id as another defense-in-depth measure against accidental misconfiguration

Current Behavior

The correctness of the watched chain can only be gathered by checking that other artifacts line up, like block height and message emission.

Possible Solution

Make the corresponding chain id at startup and periodically and error out if it does not match an expected mapping of Wormhole chain id to native chain id.