Precompiled `ArrayCopy` for `UnknownArrayHandle`

Previously, in order to copy an UnknownArrayHandle, you had to specify some subset of types and then specially compile a copy for each potential type. With the new ability to extract a component from an UnknownArrayHandle, it is now feasible to precompile copying an UnknownArrayHandle to another array. This greatly reduces the overhead of using ArrayCopy to copy UnknownArrayHandles while simultaneously increasing the likelihood that the copy will be successful.