Epic: Migrate subnet-evm repo to `grafts/subnet-evm`

[JonathanOppenheimer]

This issue tracks the migration of the subnet-evm go module to avalanchego.

TODO

• subnet-evm code ready for mono-repo
  • See Epic: Subnet-EVM code readiness for monorepo subnet-evm#1893
• All PRs posted and CI passing on the last one
  • Set-up tooling [migrate-subnet-evm][1] Add tooling enabling repo migration #4653
  • Add graft/subnet-evm [...]
  • Rewrite subnet-evm imports [...]
  • Change go mod configuration [...]
  • Migrate CI [...]
  • Automated lint [...]
• All above PRs approved and ready for merge
• Freeze subnet-evm development to prevent further changes
• Successively merge child PRs into the subtree merge PR
• Merge the initial PR
• Manually merge the subtree merge PR (otherwise history will be squashed)
• Make the new subnet-evm CI jobs required
• Close the subtree merge PR
• Archive the subnet-evm repo
• Archive the subnet-evm-internal repo
• Migrate any outstanding subnet-evm PRs as per the graft README
• Clean up graft/subnet-evm post merge (a lá chore: Cleanup coreth post-merge #4578)