I enabled vscode autocomplete in our test files. Typechecking had too many errors to enable, but it caught some real bugs that I will fix in a follow up.
This patch contains:
* `test/types.d.ts` - d.ts file for our test runner.
* `test/tsconfig.json` - typescript project for our tests.
* JSDoc header in all specs to mark the describe as a TestSuite
* Drive-by fix of a launcher test that was using `if` instead of `it`
* Some drive-by fixes of unimpactful typos in tests.
This adds support for `root` in accessibility.snapshot
firefox role names are now normalized to aria roles where they match
webkit roledescriptions are less noisey on mac
webkit mac/linux results are further defined
interestingOnly tests are replaced by one that doesn't rely on undefined behavior
the main accessibility test was split up a bit for more refined testing.
