Proxy BinarySearch methods to inner list

Being able to binary search through a sorted list is really handy at times but unfortunately ```BinarySearch``` isn't implemented as an extension method on IList<T> as it should be but rather as an List<T> only thing. By proxying this call we can make use of the nice built in methods that operate on the internal array of the inner list instead of implementing it ourselves and proxying through the index property.

I chose not to do the same for the derived lists since the main use case I have for this is to use it to guarantee sort on insertion and derived lists are read only.