[PREVIEW] XD-954: Shell code completion for stream definitions



Not ready for merge, as this requires https://github.com/ericbottard/spring-shell/tree/SHL-116-QuotesEscaping (hence changed version in build.gradle)

Sadly, does not provide completion for module names, as another refactoring would be needed in case of parse failure to know exactly what kind of module would be expected (or else we would propose false positives).

The general infrastructure is there though, and adding that will be really easy afterwards.

Still requires polishing, but it's here for you to play with