Change validation logic

Refactoring package com.icerockdev.api.Request

Migration guide:

• Replace request.isValid() and request.isValidRecursive() to request.validate() and request.validRecursive(), respectively.
• For get list of error need call request.getErrorList().

Example:

post("/object") {
          val request = call.receiveRequest<TestRequest>()
          if (!request.validate()) {
               throw ValidationException(request.getErrorList())
          }
          call.respond(TestResponse2(200, request.email, request.password))
}