TestSuite: revert multi-template support in CORRADE_COMPARE_WITH().

We don't need anything like that, as we can wrap it in parentheses:

    CORRADE_COMPARE_WITH(a, b, (Comparator<T, U>{}));

Partially reverts commit 213f00680829d24e42b7ac7f00bea54d1eca721e.
Containers: added Array::release().