Show the retry button on latest tx of earliest nonce.

[danjm]

Fixes a minor issue with the logic for when retry buttons should be displayed on transactions.

The retry button is now only ever shown on the latest submitted transaction that shares a nonce with the earliest submitted transaction.

For example:

• I creates Tx 1A, then creates Tx 2A.
• both take too long, so the retry button will appear on Tx 1A
• I retry Tx 2A first and create Tx 2B. The retry button will still only appear on Tx 1A
• I now retry Tx 1A to create Tx 1B. Once Tx 1B takes too long, the retry button will appear on Tx 1B.

[estebanmino]

looks good to me!