net/netip: add fuzz test comparing with net.ParseIP #49367
Description
There is an excellent opportunity to write a fuzzer that compares the behaviors of net and netip, to find differences in parsing, serialization, validation, and IsFoo values. Although the internals are different, we probably want them to behave the same, and to document where they diverge intentionally.
It should also catch issues such as #49365.
/cc @katiehockman