This PR creates a new test type for `run_tests.py` called `dart-host`.
The tests remaining under the `dart` type are tests that run in
`flutter_tester`. The `dart-host` tests run in the Dart CLI. This allows
`run_tests.py` to be simplified a bit, and while doing this I spotted a
couple of mistakes that were causing some tests not to run.
This PR also makes a couple of small style fixes to the build config
json files, converting tabs to spaces, and moving some "script" fields
before the "parameters" fields.
594738f2d5