1. Move contract deployment and invocation commands to the "eth" command group.
2. Remove the hack to use EAM#Create2 for an external contract creation.
3. Remove code made stale as a result of these refactors.
* Add f4 integration test and cli to generate eth addr from code
* make gen and docsgen
* fix lint
* address comments
* make gen and make docsgen sigh
* address moar comments
* use existing APIs to determine actor types
* Add IsEvmActor API
* "strings are bad" -Geoff