A PropType error was shown in the console when on the Awaiting Swap
page in certain error scenarios. The `symbol` property was sometimes
not set if `destinationTokenInfo` was missing.
The `symbol` prop has been removed, as the `AwaitingSwap` component
already selected the `fetchParams`, and the `destinationTokenInfo`
object within. The prop was effectively a duplicate.
The `AwaitingSwap` component was emitting a React warning when rendered
because a component was being rendered in an array without having a
`key` prop set.
A key has been added to the `CountdownTimer` component, which is passed
into the translation helper in an array. The warning no longer appears.
* Only format timeRemaining if in useTransactionTimeRemaining if it is truthy
* Only setTimeRemaining in useTransactionTimeRemaining if submitted time is a number
* Use isSubmitted as a check, instead of isPending and submittedTime, before calculating timeRemaining
