Increase granularity to handle disabled tests

We are currently storing test prefix(i.e., disabled, echo.disabled) information per test target in TKG, we would like to increase the granularity to each test variation. This can allow multiple enhancements including but not limited to:
- support executing disabled tests in test list
- generate disabled parallel lists
- skip disabled/skipped test in dynamic compilation

Start by tracing how TKG stores the test prefix for each test target and how test variations are represented. Map the current disabled, echo.disabled, test-list, parallel-list, and dynamic-compilation flows. Done means prefix information is stored per variation and the listed disabled-test enhancements can be supported.

Written by the indexing model from the issue text.