User should be able to add new wallet

[dnaidionov]

User should be able to add new wallet from the Home screen Wallet view (#22).
Wallet can be of one of the following types:

• Custodial
• Exchange
• Hardware
• Watchlist

When adding a wallet, user names it, selects wallet type, and specifies attributes or authorizes connection based on a wallet type (to be extended into a separate ticket for each type).

If user connects existing external wallet, upon connection, all assets in that wallet should be displayed.

Questions:

1. Should user have an option to make wallet public (e.g. watchlist)? Should this depend on a wallet type?