Fix Flakey DKG Tests

[jordanschalm]

• Changes the error message for artificially disabled DKG contract client errors, to make it clearer where these errors are coming from
• Ensures the DKGEngine<->Emulator connection is enabled at the end of the test
  • This was the ultimate source of the flakiness -- because of the number of blocks and the interval of introducing artificial failures to the dkg client, it was left in a disabled state at the end of the test. This caused a race where the DKG Engine must call SubmitResult prior to the test thread building the final blocks.

[codecov-commenter]

Codecov Report

Merging #1432 (1d4f442) into master (9d0c789) will increase coverage by 0.05%.
The diff coverage is 67.07%.

@@            Coverage Diff             @@
##           master    #1432      +/-   ##
==========================================
+ Coverage   55.41%   55.47%   +0.05%     
==========================================
  Files         512      513       +1     
  Lines       31942    32086     +144     
==========================================
+ Hits        17700    17799      +99     
- Misses      11862    11898      +36     
- Partials     2380     2389       +9     

Flag	Coverage Δ
unittests	55.47% <67.07%> (+0.05%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
cmd/bootstrap/cmd/final_list.go	8.40% <0.00%> (ø)
cmd/bootstrap/utils/file.go	0.00% <0.00%> (ø)
engine/consensus/ingestion/engine.go	45.63% <ø> (+0.12%)	⬆️
module/dkg/controller_factory.go	0.00% <0.00%> (ø)
module/dkg/broker.go	58.55% <46.80%> (-7.31%)	⬇️
module/epochs/qc_voter.go	59.67% <52.17%> (+1.34%)	⬆️
cmd/bootstrap/cmd/qc.go	50.00% <60.00%> (+7.14%)	⬆️
cmd/bootstrap/run/qc.go	46.05% <71.42%> (+2.57%)	⬆️
cmd/bootstrap/cmd/finalize.go	65.43% <76.08%> (+0.12%)	⬆️
cmd/bootstrap/cmd/rootblock.go	94.82% <94.82%> (ø)
... and 8 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a4d6955...1d4f442. Read the comment docs.

[turbolent]

Maybe include https://github.com/onflow/flow-go/pull/1427/files#diff-aac557cbcb09178f964a6cfcd0b271089f3b13a9c579297ffee790ccf6671085L312-R314 here?

[jordanschalm]

Maybe include https://github.com/onflow/flow-go/pull/1427/files#diff-aac557cbcb09178f964a6cfcd0b271089f3b13a9c579297ffee790ccf6671085L312-R314 here?

🙇 Will do, thanks for the reminder @turbolent

[jordanschalm]

bors merge

[bors]

Build succeeded:

• Integration Tests (1.15)
• Integration Tests (1.16)
• Lint
• Unit Tests (1.15)
• Unit Tests (1.16)