tests: Mark tests with AddressSanitizer-detected leaks
Various tests have leaks where it isn't clear whether the data is intentionally not freed, or leaked due to a bug. If we mark these tests as TODO, we can skip them under AddressSanitizer and get the rest to pass, giving us a baseline from which to avoid regressions. Signed-off-by: Simon McVittie <smcv@collabora.com>