build Zashi/Keystone wallet switch + flow for Connect Hardware Wallet

[true-jared]

BUILD ZASHI / KEYSTONE WALLET SWITCH:

• add Zashi/Keystone wallet switch to the header and update the Settings and Show/Hide icons globally
• upon tap on the switch, pop up a bottom sheet:
  • by default display the Zashi wallet, a promo offer button (leading to a buy URL), and a [Connect Hardware Wallet] button
  • when a user taps on the [Connect Hardware Wallet] button, they will enter the flow for adding the hardware wallet (specified below)
  • once a user has connected a Keystone Hardware Wallet, display the Zashi and Keystone wallet buttons, and allow the user to switch between the wallets
  • this global switch allows the user to:
    1. see their wallet balance and transactions in a separated view
    2. switch wallets to send transactions from
    3. view the wallet Balances and shield its funds
    4. see addresses of the wallet in the Receive tab

BUILD THE FLOW FOR CONNECTING HARDWARE WALLET:

1. a user taps on the button [Connect Hardware Wallet]
2. a user is navigated to the Connect Hardware Wallet screen

• display the explanation and steps to connect
• allow the user to navigate to a tutorial by tapping on the View Keystone Tutorial link

3. when a user taps on the [Continue] button, open Scan UI with instructions "Scan your Keystone wallet to connect" and the flashlight icon

• if a user taps on the Cancel button, route them back to Connect Hardware Wallet screen

4. once a user scans a QR code displayed on their Keystone hardware wallet, they should be routed to the next screen to confirm the wallet they wish to connect

• the button Unlock is disabled until a user checks the checkbox
• if a user taps on the button Forget this device, abort the flow, and route them back to the home screen
• once a user taps on the button Unlock, they should be routed back to the home screen and have Keystone selected in the wallet switch