Fix long path name tar encoding and decoding errors

[a-voyager]

FormatException: EOF reached without finding string terminator will be thrown with using the InputFileStream / OutputFileStream for .tar file's encoding and decoding, if any file's path name is very very long.

Minimum Reproducible Example

import 'package:archive/archive_io.dart';  

void main() async {  
  const kLongFileName = '/long_path_name/long_path_name/long_path_name/long_path_name/to/this_is_an_extremely_long_filename.bin';  

  {  
    final archive = Archive()..addFile(ArchiveFile(kLongFileName, 1, [1]));  
    final bytes = TarEncoder().encode(archive);  
    TarDecoder().decodeBytes(bytes);  
  }  

  {  
    final archive = Archive()..addFile(ArchiveFile(kLongFileName, 1, [1]));  
    final outputFile = 'output.tar';  
    TarEncoder().encode(archive, output: OutputFileStream(outputFile));  
    TarDecoder().decodeBuffer(InputFileStream(outputFile)); // FormatException: EOF reached without finding string terminator  
  }  
}

How to Fix In order to control the scope of influence (such as anywhere reading a null-terminated string), pass the size parameter to the InputStream#readString method only when failed to trying to read the null terminator.

       if (tf.filename == '././@LongLink') {
-        nextName = tf.rawContent!.readString();
+        try {
+          nextName = tf.rawContent!.readString();
+        } catch (error) {
+          nextName = tf.rawContent!.readString(size: tf.fileSize);
+        }
         continue;
       }

[brendan-duncan]

I'm closing this PR (I know it's old and I neglected it). I'm finishing a major version update, and it includes a similar fix for the tar symlink not always being null terminated. https://github.com/brendan-duncan/archive/tree/4.0