Remove array duck-typing in object/deepMatches

See https://github.com/mout/mout/commit/e030c2fccb035181991977a84df7ebd64b8a9a8e#commitcomment-2723761

This removes the check for `.length` in favor of using `lang/isArray`.

One interesting problem that I ran into was that I could not test for this behavior using an object in the target and an array in the pattern. With the new behavior it would match, since `.length` is not enumerable, and so it would only check to see that `obj["0"]` is the same.

/cc @millermedeiros @jdalton