feat(ListKeyManager): Support Signal-based Query

[keatkeat87]

Feature Description

Signal-based query doesn't return QueryList anymore, it only returns readonly Array.
so ListKeyManager should support it.

and another thing

we should have a way to watch Signal like previously watching QueryList.

Workaround:
if array will not changes, we can just cast to not readonly

const keyManager = new ListKeyManager(this.items() as FocusableOptionDerective[]);

if we need watch the array, we can access private QueryList from Signal.

const signalNode = this.items[SIGNAL] as { _queryList: QueryList<FocusableOptionDerective> };
const keyManager = new ListKeyManager(signalNode._queryList);

Use Case

No response