Add Execution Provider conformance test suite
Parameterized GoogleTest suite (EpContract/EpConformanceTest) encoding universal IExecutionProvider invariants every EP must satisfy: stable Type(), valid preferred layout, CPU mem types map to CPU-accessible devices, non-null/repeatable preferred allocators, usable allocations, CPU data-transfer round-trip integrity, and consistent metadata queries. EPs are registered via factories (no static-init construction); unavailable EPs skip rather than fail. Adding a new EP is a single guarded line in GetEpConformanceParams().
Author
Gopalakrishnan Nallasamy
