Rationalize SourceStream vs Volumes

[adamhathcock]

SourceStream now handles multiple files and streams while the intention of Volume was to represent that.

Having both abstractions seems wrong yet both are providing value.

[adamhathcock]

I probably need to create an abstraction that a stream of bytes isn't the same as a File/Stream.

7Zip can have a contiguous stream of bytes for a file or files.
Rar can have a contiguous stream of bytes for files (SOLID).
A stream of bytes can be across Files/Streams