Remove spring-integration-mqtt from master
DSL: Fix `@Autowired` issue for `IntegrationFlow`s

* Move DSL parser logic from `BFPP` to `BPP` as soon as the DSL doesn't populate any `BeanDefinition` - just real objects,
which can be registered with `this.beanFactory.registerSingleton(beanName, component);`
* Add more DSL for `Amqp` 'Namespace' factory and provide tests on the matter
* Comment out `spring-integration-jdbc` and `spring-integration-jpa` dependecies because the provide `spring-jdbc` dependency,
but it causes an issue in Boot: https://github.com/spring-projects/spring-boot/issues/1041