[mono] Support copying arrays of compatible pointers

[huoyaoyuan]

#104103 (comment)

If typeof(T*).IsAssignableFrom(typeof(U*)) is true (for example int* and uint*), coreclr allows Array.Copy from U*[] to T*[].
The managed logic has been updated in #104103. The unmanaged array_set_value_impl seems still throwing an error.