Swap and Pay scenarios should have easier to choose destination

[amessbee]

In both Swap and Pay scenarios, the user is supposed to send/swap tokens to a recipient for which a recipient address is needed. This is not very convenient for testing. It would be good idea to have readily available secondary wallet that can be used here.

• In Pay, it would perhaps be okay (and very convenient) to have a default address already filled in.
• In Swap, an approval would be needed from secondary wallet, therefore, a default address probably does not make sense. But we can point to a page in readme where two different wallets can be created to be used with this dapp.