Standard json type mapped from protobuf int64 is string

[cytommi]

JSON value will be a decimal string. Either numbers or strings are accepted.

https://protobuf.dev/programming-guides/proto3/#json

Users of protojson have also been confused by encodings for int64 types being strings.
golang/protobuf#1414

This PR should ensure that the generated docs are in line with the protobuf standard.

[solo-build-bot]

Waiting for approval from someone in the solo-io org to start testing.

[nfuden]

@shashankram how does this mesh or not mesh with discussions around the string versus int marshalling issues we had talked about .

[shashankram]

@shashankram how does this mesh or not mesh with discussions around the string versus int marshalling issues we had talked about .

Since we primarily use this library to generate Kubernetes CRD schemas, we set use x-kubernetes-int-or-string to get around this. I understand the motivation of this PR though.