Cache `/ipns/<address>` resources

[defder-su]

It makes sense to save all visited /ipfs/<address> resources to MFS /ZeroNet/ipfs.

Regarding /ipns/<address> resources, there are two possibilities:

1. Use /ZeroNet/ipfs, resolving ipns domains/addresses. All versions will be preserved.
2. Use /ZeroNet/ipns. More accurate MFS, especially in case of frequent updates.

[defder-su]

There is an idea to implement second way (more ZeroNet like way), but log all updates (when changed CID).