I should be able to speed up multiple pending transactions

Reproduce:
1. Submit two transactions with a very low gas price
2. Try to speed up the first pending transaction -> this works
3. Try to speed up the second pending transaction: the speed up button is not being shown

There is no technical reason why I shouldn't be able to speed up several pending transactions but the metamask ui doesn't let me do this.

Reproduce the issue by submitting two transactions with very low gas prices, speeding up the first, and checking the second. Trace the UI flow that decides whether the speed-up button is shown. Done means multiple pending transactions can each be sped up and the second transaction displays the button.

Written by the indexing model from the issue text.