Rename iteratesOverSequence -> iteratesAs

Rename iteratesOverSequence -> iteratesAs, and add a form that takes an `Iterable<T>`, allowing

```
List<String> iterable = Arrays.asList("foo", "bar");
ASSERT.that(iterable).iteratesAs("foo", "bar");
```

which it already allows now with the older method name, but also allows

```
ASSERT.that(iterable).iteratesAs(asList("foo", "bar"));
```

since many people may need ordered collections for expected values in more complex tests.

This PR also keeps iteratesOverSequence() for compatibility but deprecates it.