Use SeekableByteChannel instead of OutputFile/InputFile Classes

[asfimport]

Use Java NIO SeekableByteChannel for input to reader/writer instead of the current Parquet-only Output/InputFile Classes

Reporter: David Mollitor / @belugabehr

Related issues:

• Parquet without Hadoop dependencies (relates to)
• Add Java NIO Avro OutputFile InputFile (supercedes)

_{Note: This issue was originally created as PARQUET-1905. Please see the migration documentation for further details.}

[asfimport]

David Mollitor / @belugabehr: Also gets rid of PositionOutputStream