add dialect support checking to tests

this allows us to test for dialect features in tests, see
test/transaction.test.js for an example of checking for row locking
support before running a test

I know this is kind of small (and I could have combed through the rest of the tests changing things around), but I wanted to get the actual feature in before using it all over. Plus I've got a pending much larger commit to fix styling in all the tests as well :)