fvm-evm: absorb into built-in actors

[raulk]

Context and motivation

In order to ship the EVM runtime as a built-in actor, the easiest solution is to place the code inside the builtin-actors repo so that its bytecode can be included in a single bundle. This discussion in Slack had opinions on all directions: https://filecoinproject.slack.com/archives/C029MT4PQB1/p1659461336231689

Proposal

The concrete proposal here is to move https://github.com/filecoin-project/fvm-evm/ into the next branch of https://github.com/filecoin-project/builtin-actors. However, before doing that I propose the following:

• [ ] Delete the bridge and registry components, to retain only the EVM runtime
• [ ] Deploy contracts by instantiating the EVM runtime (no longer via the bridge)
• [ ] Call contracts by calling the EVM runtime (no longer via the bridge)

The bridge and registry were very useful exploration during prototype stage, but the real solution will come out of #690. If after we agree on an approach there we decide that these components were necessary in their current form, we can reintroduce them.