Add remote step execution support

[fmbenhassine]

This feature is inspired by the idea (from Hadoop, Spark, and other data processing frameworks) of moving processing code near the data rather than the opposite. By avoiding moving huge datasets over the wire, a remote step would minimize network congestion and improve computation throughput. The goal here is to add a step implementation in Spring Batch that is able to delegate the execution to a remote step.

References:

• https://en.wikipedia.org/wiki/Locality_of_reference
• https://www.thoughtworks.com/insights/decoder/d/data-locality
• https://stackoverflow.com/questions/11602699/hadoop-code-moves-near-data-for-computation
• https://stackoverflow.com/questions/40601991/what-is-the-principle-of-code-moving-to-data-rather-than-data-to-code