Randomize the `ConnectStyle` during tests

Randomize the `ConnectStyle` during tests

We have a bunch of fancy infrastructure to ensure we can connect
blocks using all our different connection interfaces, but we only
bother to use it in a few select tests.

This expands our use of `ConnectStyle` to most of our tests by
simply randomizing the style in each test. This makes our tests
non-deterministic, but we print the connection style at start so
that it's easy to reproduce a failure deterministically.