Add adapters for Java functional interfaces

[fmbenhassine]

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