validation: handler/filter for lambda routes + remove MvcValidator

[jknack]

• Remove MvcValidator. Merge content into BeanValidator
• Rename BeanValidator.validate to BeanValidator.apply (avoid method name conflict)
• Creates BeanValidator.validate() route handler/filter which intercept calls to HTTP request object and run validator
• TODO: if we agreed on merging of MvcValidator we can remove/get rid of jooby-validation module

There two ways of using validator on lambda routes:

{
    get("/do", validate(ctx -> ctx.query(Bean.class)));
}

Or with filter:

{
    use(validate());
    get("/do", ctx -> ctx.query(Bean.class));
}

[jknack]

@SentryMan @kliushnichenko one more

[kliushnichenko]

the developer experience is much better with a filter, but, the price is reflection/proxy usage, are we fine with it?
I remember you were discussing GraalVM support, is it still on the roadmap?

[jknack]

GraalVM

Nothing more was done for long time.

Let me remove reflection. I'm just lazy sometimes.

[jknack]

@kliushnichenko without reflection

[kliushnichenko]

It's a bit late, but
I realized that if the project shares both approaches (mvc/lambda)
and uses filter use(validate())
that means that MVC route beans will be validated twice...

Sharing mvc/lambda is probably not a common case, but still realistic/possible.
Maybe we should remove the filter, and keep only the handler, bc behavior is quite odd.
Or at least add a note in the documentation

[jknack]

Feel it is an odd case (like you said), but we can probably do something to fix it.

can you work and mentioned on documentation?