refactor: persist public key and derive address

[He1DAr]

Download the latest build

This refactor aims to pave the way to restructure transaction signing and use the new fee estimation mechanism.

• Persist public key, remove stxAddress and derive it from public key (closes #842)
• Add locked view: when public key is missing, wallet will show a locked screen asking for password then persist public key.
• Add initialized state
  • Remove the dependency between address/public key existence and app starting route (missing address/public key doesn't mean wallet isn't initialized)
  • At any point, we can remove the public key to lock the wallet, other wallets have this as user config (auto-lock timer).

[timstackblock]

@He1DAr @kyranjamie When I attempted to send STX from my windows machine to my Mac I got this error with the testnet build

VIDEO OF THE ISSUE https://screencast-o-matic.com/watch/c3e3qrVFNcv

[Eshwari007]

@He1DAr Good news, am not able to reproduce the error above on Windows I was also successful in sending STX to several accounts via the desktop wallet.

[andresgalante]

@Eshwari007 is this QA ready?

[Eshwari007]

@Eshwari007 is this QA ready?

@andresgalante There are couple questions which I need to address with @He1DAr ,will move the ticket thereafter accordingly.