This adds Bucket::getFileDocumentForStream() and Bucket::getFileIdForStream() methods, the latter of which was renamed from getIdFromStream().

Additionally, this replaces the getId() method in both internal stream classes with a getFile() method. The debug output for ReadableStream has also been simplified to include the entire file document instead of ID, chunkSize, and length.

Unfortunately, PHP's StreamWrapper API requires that we trigger errors instead of throwing exceptions. This will affect driver exceptions thrown during IO and CorruptFileException thrown by ReadableStream.

WritableStreams cannot be read and are never EOF. ReadableStreams cannot be written.

Unfortunately, PHP's StreamWrapper API requires that we trigger errors instead of throwing exceptions. This will affect driver exceptions thrown during IO and CorruptFileException thrown by ReadableStream.

WritableStreams cannot be read and are never EOF. ReadableStreams cannot be written.

Fixed a typo

Note: Serialization of BSON type classes (from the driver) still depends on PHPC-459.

This also improves test coverage for downloadToStreamByName().

Classes using CollectionWrapper should rely on its public API rather than work with its files and chunks collections directly.

Negative reads should throw before they cause an fread() failure. Zero-length reads can return an empty string immediately.