JIRA: https://jira.spring.io/browse/INT-4325
When channel adapter is defined without `id` attribute, the
`JpaInboundChannelAdapterParser` generates the name for class which
bean is never registered, therefore all the `JpaExecutor`s are registered
with the same bean name and afterward all the `JpaPollingChannelAdapter`
without `id` share the same `JpaExecutor`
* Generate bean name based on the `SourcePollingChannelAdapterFactoryBean`
which is used eventually for real bean registration
* Add test config for several channel adapters without `id`
* Optimize the `JpaInboundChannelAdapterParserTests` to start
the context only once during test class initialization
**Cherry-pick to 4.3.x**
cb1784d978