JsonSchema does not correspond to Serde representation

[Henry Zimmerman]

Currently, the JsonSchema trait is derived instead of manually implemented to match the parser for IpNet, IpV4Net, and IpV6Net.
This causes it to generate a schema object that indicates that for IpV4Net, the serde deserializer expects a JSON object like:

{
    "addr": "0.0.0.0",
    "prefix_len": 0
}

when in reality, the deserializer expects, and serializer produces:

"0.0.0.0/0"

This can be resolved by implementing JsonSchema manually

[krisprice]

Hi @hgzimmerman - thanks. Yeah I figured this would be needed hence asking in the original PR #31 if the default output was actually satisfactory. Since @smklein was the original requestor for this with the use case at his employer Oxide I wonder if he could weigh in here on whether this change will work for him or not? CC @ralpha and @xfbs in case they have opinions too.

Thanks

[Sean Klein]

That change works for us - the 0.0.0.0/0 format actually matches our hand-rolled implementation more closely than the derived version!

[krisprice]

Thanks @hgzimmerman and @smklein I've merged and published these fixes.

[Henry Zimmerman]

Thanks!