Introduce TCollections.CreateEnumerable<T> method

[Zuo Baoquan]

It often happens that I would like to convert a value of TArray<T> to IEnumerable<T>. Instead of using TArrayIterator<T> in Spring.Collections.Extensions, It will be easier to introduce it in TCollections.

[Stefan Glienke]

I added an overload for the TCollections.Query<T> method that does that.