Onchain swaps from inside rotki

[LefterisJP]

Abstract

With onchain send inside rotki we now need to have a way for users to swap tokens from inside rotki. An onchain swap.

Motivation

The motivation is to be able to do all your onchain interactions from inside rotki. To love the app and stay inside all the time. Also to try and get some extra revenue from positive slippage given by the various aggregators much like our friends at defillama do here: https://swap.defillama.com/

Specification

• [ ] Add onchain swap in the UI under the onchain send
• [ ] Integrate with various aggregators much like defillama does with their swap
• [ ] Implement the logic in the backend to faciliate all this.

Probably will need more details here in the spec as we start developing it and also as we contact the various aggregators.