Handle two or more pre-confirmations at the same slot in the demo

[thedevbirb]

There is an edge case in the frontend demo where sending two pre-confirmations rapidly in the same slot can cause the second one to fail with NonceTooLow error.
This is due to fact the nonce is obtained from the provider i.e. the execution state, which hasn't processed the pre-confirmed transaction yet, and as such the nonce of same transaction is the same of the first one.

In order to solve this, in the frontend we should increment the nonce of the account upon receiving the commitment from the sidecar

[mempirate]

Maybe this can help: https://x.com/_jxom/status/1802851459072925900

[thedevbirb]

On the sidecar there was an incorrect nonce inserted in the state diff, which has been fixed with the following commit: d074de9 (#62).