Delete keys works wrong

[ilanolkies]

Now, when we click on 'delete master key', we need to reset the app and even the PIN is not deleted. We should implement deleteKeys in such way that it

• deletes the mnemonic
• deletes the PIN
• updates the state properly to prevent need of reloading the app

[jessgusclark]

It should delete all of the RN Storage including the items above and the RNS domains associated with it.

[jessgusclark]

One more thing I noticed, two screens currently have access to the deleteKeys function. I think only one of them actually needs it.