Add the exchange rate field to the transaction details page

[Nana-EC]

Problem

It's currently not obvious to users when the exchange rate changes.
On Hedera this can happen in between a users transaction since it comes in the form of a File update.
Users are occasionally thrown off by this as it's not clear what changed in between transactions.

Solution

Add an exchange field to a transaction page so a user is made aware what rate was used to go from HBAR to $'s

Alternatives

No response