Need an option to include "empty air" sections in Block/Biome VolumeStreams

[gabizou]

Volume Streams are fantastic at optimizing when a chunk section has effectively still returned as an empty section, and because it's effectively "air", we still may want to copy that "air" to the new area, or at least populate the stream with air sections.

This is a two part issue, one is API where we need to expose the option to include air/empty sections within the range, and the second is the implementation of this on the generic parameters for streams.