Add ability to dynamically change addresses

[lousando]

Allow the user to swap between different addresses stored on the Trezor.

• This would mean dequeuing active transaction and balances requests that are in flight to avoid dreaded balance bugs or wrong transaction list bugs.
• In addition, Briskett would need to ask the user for all their addresses ahead of time instead of 1.

[Tarskin]

One could show all addresses, after exporting the public keys from the Trezor, before letting a user select an address (or multiple addresses) to interact with. This way you avoid having to build some clunky 'switching' interface, and instead you just have a flow that restricts adresses (e.g., get public key, list all 7 addresses (with their balance), let user select 1-n adresses, get private keys for selected addresses and then the final page allows the user to interact with the selected adresses).

I will play around a bit more this week, to see if I can get it running locally to connect with the node to see if I can make some headstart with this (JS is not my main language, so will take a bit).