Add option to support nestjs ValidationPipe

[ramiloif]

ValidationPipe support might save many programs time since nestjs has already validation pipe mechanism.

My suggestion is to add an optional decorator for activity input for example:

    @Activity()
    async submitOrder(@Payload() order: Order) {    
    }

And in cast this input param Payload exists add class-validator validation to the function before injecting it to the worker.

Or any other idea.

In the activities part it's a bit more complicated not sure how.

If you find this idea relevant I will be glad to contribute