IPC contracts redesign

[LePremierHomme]

This epic outlines migration phases from IPC's multi-tenant, omnibus Solidity contracts to a hybrid architecture:

• child subnets to use Rust-native Platform Actor for managing its functionality consensus state
• root network deployment with consolidated Solidity contracts

More info can be found here: https://www.notion.so/IPC-redesign-proposal-2ed2ea98c236800eaa2eea8f004d18d5

[linear]

IPC-376