Some fixes to SqlQueryTestBase

[roji]

/cc @ajcvickers

[roji]

@ajcvickers made a couple more changes there, it's a bit odd we don't actually override NormalizeDelimiters* for SQL Server to not change the brackets to double-quotes (but SQL Server also accepts double-quotes so it works)

[ajcvickers]

Why is that odd?

[roji]

Well we generally use brackets everywhere for SQL Server, but not here. That means we get mixed queries out, with SQL fragments using double-quotes and EF-generated SQL using brackets. Also it begs the question of why the SQL in the tests uses brackets in the first place, when no provider actually preserves them.

[ajcvickers]

@roji I misread your first comment. Yeah, agree that is odd. I would expect us to always use brackets on SQL Server.