dfsclient should utilize dafilesrv commcompression

/* Notes on protocol:
*

• A JSON request with these top-level fields:
• "format" - the format of the reply. Supported formats = "binary", "xml", "json"
• "handle" - the handle of for a file session that was previously open (for continuation)
• "commCompression" - compression format of the communication protocol. Supports "LZ4", "LZW", "FLZ" (TBD: "ZLIB")
• "replyLimit" - Number of K to limit each reply size to. (default 1024)
• "node" - contains all 'activity' properties below:
  *
• For a secured dafilesrv (streaming protocol), requests will only be accepted if the meta blob ("metaInfo") has a matching signature.
• The request must specify "filePart" (1 based) to denote the partition # being read from or written to.
  *
• "filePartCopy" (1 based) defaults to 1
  *
• "kind" - supported kinds = "diskread", "diskwrite", "indexread", "indexcount" (TBD: "diskcount", "indexwrite", "disklookup")
• NB: disk vs index will be auto detected if "kind" is absent.
  *
• "action" - supported actions = "count" (used if "kind" is auto-detected to specify count should be performed instead of read)
  *
• "keyFilter" - filter the results by this expression (See: HPCC-18474 for more details).
  *
• "chooseN" - maximum # of results to return
  *
• "compressed" - specifies whether input file is compressed. NB: not relevant to "index" types. Default = false. Auto-detected.
  *
• "input" - specifies layout on disk of the file being read.
  *
• "output" - where relavant, specifies the output format to be returned
  *
• "fileName" is only used for unsecured non signed connections (normally forbidden), and specifies the fully qualified path to a physical file.
  *
  */
  void cmdStreamCommon(IPropertyTree *requestTree, MemoryBuffer &rest, MemoryBuffer &reply, CRemoteClientHandler &client, CClientStats &stats)
  {
  /* Example JSON request:
  *
• {
• "format" : "binary",
• "handle" : "1234",
• "replyLimit" : "64",
• "commCompression" : "LZ4",
• "node" : {
• "metaInfo" : "",
• "filePart" : 2,
• "filePartCopy" : 1,
• "kind" : "diskread",
• "fileName": "examplefilename",
• "keyFilter" : "f1='1 '",
• "chooseN" : 5,
• "compressed" : "false"
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• "output" : { * "f2" : "string", * "f1" : "real" * }
• }
• }
• OR
• {
• "format" : "binary",
• "handle" : "1234",
• "replyLimit" : "64",
• "commCompression" : "LZ4",
• "node" : {
• "kind" : "diskread",
• "fileName": "examplefilename",
• "keyFilter" : "f1='1 '",
• "chooseN" : 5,
• "compressed" : "false"
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• "output" : { * "f2" : "string", * "f1" : "real" * }
• }
• }
• OR
• {
• "format" : "xml",
• "handle" : "1234",
• "replyLimit" : "64",
• "node" : {
• "kind" : "diskread",
• "fileName": "examplefilename",
• "keyFilter" : "f1='1 '",
• "chooseN" : 5,
• "compressed" : "false"
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• "output" : { * "f2" : "string", * "f1" : "real" * }
• }
• }
• OR
• {
• "format" : "xml",
• "handle" : "1234",
• "node" : {
• "kind" : "indexread",
• "fileName": "examplefilename",
• "keyFilter" : "f1='1 '",
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• "output" : { * "f2" : "string", * "f1" : "real" * }
• }
• OR
• {
• "format" : "xml",
• "node" : {
• "kind" : "xmlread",
• "fileName": "examplefilename",
• "keyFilter" : "f1='1 '",
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• "output" : { * "f2" : "string", * "f1" : "real" * }
• "ActivityOptions" : { // usually not required, options here may override file meta info. * "rowTag" : "/Dataset/OtherRow" * }
• }
• OR
• {
• "format" : "xml",
• "node" : {
• "kind" : "csvread",
• "fileName": "examplefilename",
• "keyFilter" : "f1='1 '",
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• "output" : { * "f2" : "string", * "f1" : "real" * }
• "ActivityOptions" : { // usually not required, options here may override file meta info. * "csvQuote" : "\"", * "csvSeparate" : "," * "csvTerminate" : "\\n,\\r\\n", * }
• }
• OR
• {
• "format" : "xml",
• "node" : {
• "action" : "count", // if present performs count with/without filter and returns count
• "fileName": "examplefilename", // can be either index or flat file
• "keyFilter" : "f1='1 '",
• "input" : { * "f1" : "string5", * "f2" : "string5" * }

  ,

• }
• }
• OR
• {
• "format" : "binary",
• "handle" : "1234",
• "replyLimit" : "64",
• "commCompression" : "LZ4",
• "node" : {
• "kind" : "diskwrite",
• "fileName": "examplefilename",
• "compressed" : "false" (or "LZ4", "FLZ", "LZW")
• "input" : { * "f1" : "string5", * "f2" : "string5" * }
• }
• }
• OR
• {
• "format" : "binary",
• "handle" : "1234",
• "replyLimit" : "64",
• "node" : {
• "kind" : "indexwrite",
• "fileName": "examplefilename",
• "input" : { * "f1" : "string5", * "f2" : "string5" * }
• }
• }
  *
  */