Revert #22 and fix pallet issues with most recent changes to AHM

rel: https://github.com/paritytech/asset-hub-migration-monitor/pull/22

The following PR add some urgents fixes for a deploy - we should revert them and correctly update the code as needed. In addition to that, some of the api's have changed - we need to fix them to ensure the dashboard is working correctly.