Implement an x-bridge dashboard

[DrZoltanFazekas]

The dashboard

• must display the history of completed x-bridge transactions as well as the tokens and amounts in transit
• must display the amount of each bridged token locked in the token manager contract on the source chain
• must display each bridged token's circulating supply minted by the token manager contract on the target chain
• should display stats on the average gas fee spent on each target chain so that we can adjust the chain-specific flat fee if needed