Add proto json rendering / binding

[Jarch09]

This adds the ability to directly render protobufs as JSON and bind to / unmarshal JSON payloads as protobufs.

Adds:

func (c *Context) ProtoJSON(code int, obj any) {
	c.Render(code, render.ProtoJSON{Data: obj})
}

func (c *Context) ShouldBindProtoJSON(obj any) error {
	return c.ShouldBindWith(obj, binding.ProtoJSON)
}

We need these new methods, because standard JSON encoding doesn't work with protobufs.

[Jarch09]

@appleboy @kszafran - this seems like a quick win that doesn't break other stuff. Can you please give this a quick review?

[appleboy]

I will take it.

[Jarch09]

@appleboy - any chance you can review this? Should be pretty painless ;-)

[Jarch09]

@appleboy @kszafran - this seems like a quick win that doesn't break other stuff. Can you please give this a quick review?

Heyyy sorry following up on this. Can someone please review this PR?

[kszafran]

@Jarch09 I'm not a maintainer, I can't do anything here 😅

[Jarch09]

@Jarch09 I'm not a maintainer, I can't do anything here 😅

Understood. @appleboy @thinkerou

[lukaszo]

@thinkerou @appleboy @Jarch09, can I somehow help with merging the PR?

[Jarch09]

@thinkerou @appleboy @Jarch09, can I somehow help with merging the PR?

Would love to get this merged in... lmk what needs to be done