Make a signing approval and transaction a single UI flow

[saledjenic]

Make signing approval/s and transaction/s as a single click action, without the need for a user to go explicitly through the authentication/signing flow more than once.

An example:

• At this moment swap tx cannot be placed if an approval is needed before that approval gets confirmed. That's currently done as a two-step process, firstly the user signs an approval, then waits for it to be confirmed then signs sending swap tx.
• The idea is to let the user do the signing only once and the backend should take care of the TXS order and if needed wait for their execution before placing other txs.