dbt build: Change the way we handle tests (if parent test fails then don't run non-test children)

[iknox-fa]

This work was finished, however it had to be removed from the PR due to difficulties with how some (many) of our tests operate. Because the tests don't build a correct graph failures occurred when running those tests. The obvious fix is to re-write those tests but it was too many to do as part of the dbt build effort.

References:

• Branch with operational blocking feature and broken tests.
• Discussion about why the tests caused it to hang

[jtcohen6]

It looks like the particular commits we'd want to cherry-pick and revive are 4dc2963 + aaac5ff

[jtcohen6]

Exit criteria via example:

• model_a has two children: a unique test and model_b
• The unique test should run before model_b
• If the unique test fails, model_b should skip running
• The overall dbt build command should keep running

18:49:43 | Concurrency: 1 threads (target='dev')
18:49:43 |
18:49:43 | 1 of 7 START view model dbt_jcohen.model_a........................ [RUN]
18:49:43 | 1 of 7 OK created model dbt_jcohen.model_a........................ [INSERT 2 in 0.09s]
18:49:43 | 2 of 7 START test unique_model_a_id............................... [RUN]
18:49:43 | 2 of 7 FAIL test unique_model_a_id................................ [FAIL in 0.12s]
18:49:43 | 3 of 7 SKIP relation model_b...................................... [SKIP]
18:49:43 | 4 of 7 START relation another_model............................... [START]
... and so on ...