Allow passing test options using ---

[michaelpj]

At the moment, you have to pass options to test suite executables with --test-options. This is a bit inconvenience since you often have to quote the options, and then escape quotes inside them.

We could instead allow providing options to the test suite after ---. This is a fairly standard CLI idiom, and already works for cabal run.

An argument against is that cabal test can take multiple components to test and it would have to give them all the same arguments, which might not be appropriate, but the same is true today of --test-options.

[fendor]

I think this looks a lot like #6198

[michaelpj]

Yep, it's a dupe.