Migrate keystore to Metamask eth-keyring-controller

[hashmesan]

Motivation

To improve security of the storage, I'm proposing to use eth-keyring-controller which provides a unified enclave like way to sign transaction. The enclave/controller prevents any leakage of privateKey, stores multiple type of keyring in a standard way, and provide proper lock & unlock (Lock removes all the private key in memory store, which makes secure!)

Tasks

• [x] evaluate the impact on the code
• [ ] need event passing between popup & background for add/remove wallet, and get wallets
• [ ] migrate function
• [ ] migrate UI
• [x] add wallet functionality
• [x] serialization of keyring-controller and meta data
• [ ] integrate wallets to the wallet menu UI
• [ ] integrate wallets to export UI
• [ ] integrate wallets to create UI
• [ ] integrate wallets to import UI
• [ ] signing transaction
• [ ] test with stake/unstake
• [ ] personal sign
• [ ] lock / unlock functionality
• [ ] regression testing on app
• [ ] test for injected script (API)
• [ ] alpha testing
• [ ] build & release

[hypnagonia]

@hashmesan nice proposal. we cease further wallet development and plan to migrate users to other wallets