Update Queries to exclude testnets

Currently https://nodewatch.io/ reports all beacon nodes but it's also including the testnets. Perhaps one could distinguish the two if it is that the testnets are to be included but otherwise I think it may be more intuitive to include only the mainnet nodes.

Start at nodewatch.io and trace how its queries gather beacon nodes. Determine how testnet nodes are identified, then update the query behavior so mainnet nodes are shown by default or the two networks are clearly distinguished. Done means testnet nodes are no longer incorrectly included with mainnet results.

Written by the indexing model from the issue text.