* Add Java DSL for R2DBC module * Add JavaDocs for R2DBC component setters * Introduce a `R2dbcMessageSource.SelectCreator` to narrow a `StatementMapper` API access from SpEL * Add missed `package-info.java` into R2DBC packages * Add `hamcrest-core` as test dependency into SI-R2DBC since Awaitility doesn't work without it * * Add `@NonNullApi` to R2DBC packages