Add example options for most types

[sudorandom]

This PR adds an example field for many types. Examples are no-op constraints that allow you to declare what an example value for each field may look like. These values SHOULD match the other constraints. It's planned that a buf lint rule will check these values to see if they do, in fact, validate given the other constraints on the field. Here are the types that this was added to:

• float
• double
• int32
• int64
• uint32
• uint64
• sint32
• sint64
• fixed32
• fixed64
• sfixed32
• sfixed64
• bool
• string
• bytes
• enum
• duration
• timestamp

All fields are repeatable, to allow for multiple examples. I'm unsure if there is a better way to have a no-op constraint other than expression: "true", so please let me know if I can just exclude expression altogether or if there is another way to do that. This resolves #237.

[rodaine]

I'm unsure if there is a better way to have a no-op constraint other than expression: "true", so please let me know if I can just exclude expression altogether or if there is another way to do that.

The cleanest noop is not setting anything, but yeah a CEL expression of true is probably the easiest (though I know protovalidate-go will optimize it all away).

[sudorandom]

@rodaine I noticed the CI is failing. I've also had issues with CI with a pull request against the buf repo. Is it because the PR is not from someone on the buf org or something?

Error: Resource not accessible by integration - https://docs.github.com/rest/issues/comments#create-an-issue-comment

[rodaine]

Yeah I think so. Letting the team know about it. Might just be a configuration issue.

[rodaine]

Fix in flight: bufbuild/buf-action#64

[sudorandom]

@rodaine oh, right. It got to the next error. I was wondering if I should check in changes to MODULE.bazel.lock. I guess so?

[rodaine]

Oh man it looks like you hit a bunch of landmines. One sec while I update golangci-lint.

[rodaine]

Thanks, @sudorandom!