test_vulkan: Improve device local memory testing

test_vulkan skips device local memory testing unless the --useDeviceLocal flag is passed. Delete this flag, and add testing for device local memory types when appropriate.

Additionally, improve logging and reporting when subtests are skipped. It is possible that without --useDeviceLocal the buffer and image tests appear to run and pass, but skip running any workload.

Start with the test_vulkan device-local-memory tests and trace how the --useDeviceLocal flag controls buffer and image workloads. Confirm the expected behavior for device local memory types and review the existing subtest skip logging. Done means the flag is gone, applicable memory types are exercised, and skipped subtests clearly report that no workload ran.

Written by the indexing model from the issue text.