Add adapters for Java functional interfaces

As of v5.1, Spring Batch provides an adapter for `java.util.function.Function` to an item processor. This is the only adapter available in the library for now. The goal of this feature request is to enrich the package with adapters for:

- `java.util.function.Supplier` as item reader
- `java.util.function.Consumer` as item writer
- `java.util.function.Predicate` as a filtering item processor