Adds a default validation exception handler

[SentryMan]

Resolves #669 by adding a default handler via the inject plugin

[SentryMan]

@mechite how's this?

[mechite]

@SentryMan hard to review on a phone 🤣 I like it

[mechite]

@SentryMan I'm reviewing here now on a computer.

1. RFC 9457 says that we should use application/problem+json or application/problem+xml` MIME types when using these standard error responses

2. It also states:

   The type URI is allowed to be a non-resolvable URI

   therefore, we actually don't need to point to the Avaje website.

We can do something like: tag:io.avaje.validator.constraints.Size#min, using the tag: URI scheme (not 100% sure how it's meant to be used).
But we can also just find a fluent way of excluding the "avaje" name from the response.

@SentryMan I see JSON Schema for HTTP Problems which is a specification for how the responses are meant to look.
Unfortunately, this schema is not published anywhere (for example the parent JSON Schema is published here].

While the following doesn't exclude the "avaje" name from the response, it does make it more abstract:

If we upload this schema to avaje.io/rfc9457.json, and put that into the response "type":, we get something that "has nothing to do with" / "is abstract to" the use of avaje, but is just a JSON description of what the response is meant to look like.

[SentryMan]

We can do something like: tag:io.avaje.validator.constraints.Size#min, using the tag: URI scheme (not 100% sure how it's meant to be used).

idk what to make of this statement

[mechite]

"your data failed the vibe check"

this guy

idk what to make of this statement

I mean that we basically can just point to a class file in Avaje, instead of a web URL

Ideally to me, this JSON schema I said that the RFC contains, could have been uploaded to e.g. ietf.org,
so our APIs written using avaje aren't now announcing to everyone who sends a bad request that
we are using avaje...
It's not a big deal or issue at all.

If we upload this schema to avaje.io/rfc9457.json

This suggestion was to say that we upload the official JSON schema, which is probably more useful
than pointing to the documentation of validator

[mechite]

d55a7a6 - OK, but we better verify that this is indeed valid for the tag: URI

[mechite]

a9d93ff

// Custom serialize so we don't need any json lib

Would this really be worth it over adding json-core or even full jsonb - since they have streaming writers?
Those libraries are so small and most people would have them anyway

[SentryMan]

Would this really be worth it over adding json-core or even full jsonb - since they have streaming writers? Those libraries are so small and most people would have them anyway

nahhh it's probably fine

[mechite]

🤣 he says it's fine, then optimizes anyway