Exclude unused ph-masterdata from phase4-lib

[gregjotau]

Fixes #390.

phase4-lib needs ph-tenancy for AbstractBusinessObject and IBusinessObject, but no Phase4 source uses the transitively supplied ph-masterdata API. This focused exclusion keeps the required tenancy dependency and avoids adding an unrelated 1,504,207-byte (1.43 MiB) JAR to every downstream runtime.

This is intentionally an exclusion on the Phase4 dependency edge rather than a change to ph-tenancy: other direct consumers of ph-tenancy may legitimately need its master-data integration.

Validation:

• mvn -pl phase4-lib -am verify: 132 tests, 0 failures/errors
• mvn verify: all 27 reactor modules successful
• dependency tree no longer contains com.helger.masterdata:ph-masterdata
• ReAI full build and real Peppol-enabled application startup verified without the JAR

[phax]

The changes were done by splitting submodules in ph-masterdata. Closing this one