Implement EVM support in Linera

[MathieuDutSik]

We want to make Linera a multi-VM system. The first VM to support would be the Ethereum Virtual Machine.

The Ethereum smart contracts can call other Ethereum smart contracts via call/delegatecall/staticcall. Those externally called smart contracts are not known at the deployment and they can change during runtime. Therefore, the only way to implement it is to have a global state like in Ethereum that can be accessed and run on. This can be implemented as a

A specific microchain would therefore have an Ethereum part. We would therefore need to have functions for deploying a smart contract, doing a transaction, and so on. It seems unavoidable that we have to implement the API from JSON_RPC. At first a limited part of it. In the request, the specific Microchain would have to be put.

Next is to implement the external calls. This covers two things:

• Calling external Wasm smart contracts on the same microchain.
• Calling other Ethereum smart contracts on other microchains.