The `shift-list-item` component for displaying ShapeShift transactions
has been removed, along with three other components that were used
solely by that component (`copyButton`, `eth-balance`, and
`fiat-value`).
This component hasn't been used in some time, as ShapeShift
transactions no longer exist to display. The controller that ShapeShift
transactions originated from was removed in #8118, and it became
impossible to create new ShapeShift transactions from within MetaMask
in #6746
Implement `eth_decrypt` and `eth_getEncryptionPublicKey`. This allows decryption backed by the user's private key. The message decryption uses a confirmation flow similar to the messaging signing flow, where the message to be decrypted is also able to be decrypted inline for the user to read directly before confirming.
