Bump Repo Version and Provide Migration before strict Cid code lands

Right now https://github.com/ipfs/go-ipfs/pull/4751 is providing a stop-gap measure to avoid allowing insecure hashes. Things won't break, but the insecure hashes will become useless. Once the strict Cid code (https://github.com/ipfs/go-cid/pull/40) lands things will likely break badly if there are any insecure hashes. I recommend we bump the repo version and provide a migration tool that just checks and aborts in there are any CID's with insecure hashes.

I also suggest, though not require, we provide a tool to automatically convert the insure hashes to a secure hash so that data is not lost. The same tool can just offer to delete them instead.