Support `Fill` for `ArrayHandleStride`

Previously, if you called Fill on an ArrayHandleStride, you would get an exception that said the feature was not supported. It turns out that filling values is very useful in situations where, for example, you need to initialize an array when processing an unknown type (and thus dealing with extracted components).

This implementation of Fill first attempts to call Fill on the contained array. This only works if the stride is set to 1. If this does not work, then the code leverages the precompiled ArrayCopy. It does this by first creating a new ArrayHandleStride containing the fill value and a modulo of 1 so that value is constantly repeated. It then reconstructs an ArrayHandleStride for itself with a modified size and offset to match the start and end indices.

Referencing the ArrayCopy was tricky because it kept creating circular dependencies among ArrayHandleStride, ArrayExtractComponent, and UnknownArrayHandle. These dependencies were broken by having ArrayHandleStride directly use the internal ArrayCopyUnknown function and to use a forward declaration of UnknownArrayHandle rather than including its header.