Improve wording of browser notifications

Suggested improvement on the chrome pop-up confirming a transaction:

Currently the pop-up states "Transaction #X" is confirmed. With X being the number of the transaction from that user's ethereum address. Even better if instead of the transaction number, other metadata could be used as the description for the transaction confirmation - such as the dapp or browser the transaction was occuring on, the token that was transferred etc.

E.g., instead of Alice conducting a 6th transaction from her Ethereum address to purchase a Cryptokitty and the pop-up stating "Transaction 6 Confirmed" --> "Cryptokitties Transaction Confirmed".

Can enable better UX and ensure that if users are conducting ethereum transactions across multiple platforms in the same time frame, they can know which or where the transaction took place.

Start at the Chrome transaction-confirmation pop-up and trace how its current transaction number is assembled. Review which metadata is available for the dapp, browser, and transferred token, then determine a specific description and validation criteria with maintainers. Done means the confirmation identifies the transaction clearly across concurrent Ethereum activity and has coverage for the selected wording.

Written by the indexing model from the issue text.