needs #1248

• decode the event store and loop through all events. group all events by extrinsic which triggered them. treat events from intrinsics separately
• for each extrinsic, look up the system.extrinsicSuccess or system.extrinsicFailed and log the error index
• (nice to have) translate error to human-readable for the enclave log (look up index in metadata)

Implement this such that it is easy to subscribe to any kind of event, either by extrinsic or globally

this task is done upon successful e2e demo of at least one succeeding and one failing extrinsic (failure can be provoked by committing an exchange rate to the teeracle pallet without being whitelisted:
https://integritee.subscan.io/extrinsic/2315592-3