Update Payment Hub EE dependencies

The Mifos Payment Hub EE (PH-EE) is a massive ecosystem with about 42 Java repositories that run the open-source DPI payment infrastructure. But there’s a problem: over the years, these components have drifted apart. We have a mix of everything: Java 8 to 17, Spring Boot 2.1 to 3.2, and the old javax.* namespace. This mess makes the platform hard to maintain, full of security risks (CVEs), and prone to dependency hell where one tiny conflict can break the whole stack. My goal for this GSoC is to fix this once and for all. I will lead a systematic migration to a modern, unified baseline: Java 21, Spring Boot 3.4, Apache Camel 4, and Jakarta EE 10. To be sure that everything is perfect, the project introduces a three-level test framework: a BOM verification step (classpath purity check that fails on any javax.* artifact), WireMock + Cucumber integration tests for behavioral equivalence validation, and an end-to-end smoke test via Mifos Gazelle against a live k3s deployment. A platform BOM and a connector starter template standardize dependency governance and build configuration across all components, so the unified baseline remains enforceable after GSoC ends.