[pdb] Print out some more info when dumping a raw stream.

We have various command line options that print the type of a
stream, the size of a stream, etc but nowhere that it can all be
viewed together.

Since a previous patch introduced the ability to dump the bytes
of a stream, this seems like a good place to present a full view
of the stream's properties including its size, what kind of data
it represents, and the blocks it occupies.  So I added the
ability to print that information to the -stream-data command
line option.

llvm-svn: 281077