Integration tests are messy and full of commented code

[alexjpwalker]

Problem to Solve

The integration test package is messy and full of commented code.

Proposed Solution

• Many of the comments say "re-enable when X is implemented". X is, in fact, typically implemented, so we should simply be able to uncomment them (and presumably update them to 2.0 syntax)
• The parallelQueriesInTransactionTest can most likely be simplified. While we do want the queries to be quite heavy in order to verify that the issue it highlighted (non-threadsafe use of StreamObserver) is actually resolved, there seems to be a lot of code duplication in this test.
• integration/concept is no longer needed.

[lolski]

Should the label be bug or refactor @alexjpwalker ? From what I see, it's about enabling disabled tests, updating the syntax and simplifying the test structures.

[alexjpwalker]

@lolski Updated to feature and refactor as there is a bit of both involved (regarding tests as features)

[haikalpribadi]

Being too precise by adding both feature and refactor is not actually helpful as it becomes confusing @alexjpwalker. I think just labelling it refactor here, as it is more of a refactor, is much clearer.