Proof of concept for extra streaming support

[pmqs]

I have an implementation for IO:Compress::Zstd and IO:Uncompress::Zstd in progress, using Compress-Zstd to handle the low-level compression/uncompression, but there are a couple of things I’m blocked on.

The exiting interface for streaming uncompression will either uncompress successfully or croak on error. I need a way of knowing when a frame has been completely uncompressed. Without that I have no way of telling if the compressed data stream has been truncated. I have a generic test harness that all the IO::Compress/Uncompress modules share. One set of tests checks that I can detect truncated content.

This change is a proof-of-concept that add the following

1. Add a status method for the streaming interface.
   This method returns the actual value returned from the streaming API calls.
2. Adds an isEndFrame method.
   This is the key method I need
3. Exposes the isError & getErrorName functions from the ZSTD api.
   These make error reporting easier for me.

With the above changes I can get IO:Compress::Zstd and IO:Uncompress::Zstd to build & pass all tests.

[pmqs]

I've just received another request to add Zstd support to the IO:Compress::* modules.

Any progress at your end in enhancing Compress::Zstd?

[pmqs]

Hey @spiritloose - any idea if this issue will get addressed? I'm going to fork & create a new distribution with the fix included.

Would really prefer the fix in your code, but this issue has blocked progress on getting Zstandard into the IO::* compress infrastructure.