Fixes https://github.com/spring-projects/spring-integration/issues/3656
* Move `JavaUtils` from `util` package to the root one to break any possible
tangling to/from other packages.
* Deprecate an existing `JavaUtils` for backward compatibility
* Remove `@IntegrationConverter` from the `JsonNodeWrapperToJsonNodeConverter`
and register it manually in the `ConverterRegistrar`.
The bean registration for the `JsonNodeWrapperToJsonNodeConverter` must be removed
in the next `6.0`
* Remove usage of `IntegrationContextUtils` from the `support` package
fc7d338302