Move API and VM crates from anorth/fvm-workbench into this repo

[anorth]

The fvm-workbench is a testing platform that executes actor code on a stand-alone VM. It is especially useful for gas tracing.

Two of its three crates are independent of the built-in actors. Its API defines an API that is also implemented by the built-in actors integration test VM (that exercises actors as non-WASM). That API is currently duplicated as we have elected not to have the built-in actors repo depend on that workbench. After moving the crates in to this repo though

1. it will be reasonable for the built-in actors to import it, removing the duplication
2. it will be much easier to keep all three in sync as the VM changes

The third crate depends on the built-in actors repo in order to import its integration tests and execute them. We don't want to move that one in here, but have it depend on the moved API crates.

This repo already has some testing infrastructure. I believe our long term wish is to remove it in favour of the fvm-workbench. That might need to be incremental, rewriting the internal tests that use it to use the new thing instead.

See also discussion https://filecoinproject.slack.com/archives/C015KQQLQQ1/p1697750224746249

FYI @Stebalien @aarshkshah1992