WIP Actors v6 plan

[ZenGround0]

This is a work in progress issue that will be edited to incorporate inevitably changing priorities and better information

Changes

Stability

Technical debt
Optimizations
test-vector format extension for more conformance tests
Logging
Testing

TODO track concrete issues here, most will be carried over from v5 tracking issue, some still need to be filed

Scalability

Miner state size scaling
Scaling market actor to many deals

TODO learn about and design solutions, file issues and track here

Features

FIPs for making the network better that require actors changes

TODO shepherd existing FIPs and propose new ones with highest positive impact. File actors issues and track here.