Find root cause of unhandled discv5 exceptions

[acolytec3]

We've been seeing unhandled exceptions thrown by discv5 with errors like

    at callback (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/service/service.ts:466:20)
    at SessionService.rpcFailure (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/service/service.ts:1000:6)
    at SessionService.emit (node:events:514:28)
    at SessionService.emit (node:domain:489:12)
    at SessionService.failSession (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/session/service.ts:844:14)
    at SessionService.failRequest (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/session/service.ts:827:10)
    at SessionService.handleRequestTimeout (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/session/service.ts:784:12)
    at TimeoutMap.onTimeout (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/session/service.ts:153:12)
    at Timeout.<anonymous> (file:///home/jim/development/ultralight/node_modules/@chainsafe/discv5/src/util/timeoutMap.ts:30:16)
    at listOnTimeout (node:internal/timers:569:17)

This is likely a bug in discv5 but not 100% clear yet.

[acolytec3]

Have opened this issue on the discv5 library and waiting a response before we can address this.