LibCore: Add a gzip implementation

Author: https://github.com/msc94 🔰
Commit: 4fe5503b17
Pull-request: https://github.com/SerenityOS/serenity/pull/750
Reviewed-by: https://github.com/awesomekling

Libraries/LibCore/CGzip.h

@@ -0,0 +1,9 @@
+#include <AK/ByteBuffer.h>
+#include <AK/Optional.h>
+#include <AK/String.h>
+
+class Gzip {
+public:
+    static bool is_compressed(const ByteBuffer& data);
+    static Optional<ByteBuffer> decompress(const ByteBuffer& data);
+};