Improve integration test build matrix configuration

Integration tests have various combinations of flags in order for them to run:

- `mode` (e.g. `stable`, `live`, `disable-wallet-api`) -- all modes except for `live` imply `stable`
- For live tests, CLI args enable/disable wallet tests and whether networking is disabled on the node

And in the test methods we check for these flags on or off to decide between running the test or not. Some tests will add certain test cases based on certain flags.

As the combinations of runtime options for integration tests grows, this does not scale. Devise a better way to handle the matrix of combinations.