There were three cases where execution unintentionally continued after
an error was encountered. These cases likely are impossible to
encounter in practice due to recent validation improvements in the
`eth-json-rpc-middleware/wallet` module, but they were broken
nonetheless.
Execution inside the Promise constructor now halts immediately after
`reject` is called.
Each "message" requiring a user confirmation has a unique `type`
property. These `type` properties have all been added as enums, and the
enum is now used wherever the literal string was used previously.
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.
