DataFileList format in Origdatablock files request

[abdellah257]

Summary

The request GET /origdatablocks/fullquery/files return dataFileList object as a JSON dict and not an array.
This results in an inconsistent result with OutputOrigDatablockDTO.

Current Behaviour

{
	"_id": "1b2XXX",
	"createdBy": "",
	"updatedBy": "",
	"ownerGroup": "",
	"accessGroups": [],
	"isPublished": false,
	"datasetId": "DS-XX",
	"size": 0,
	"chkAlg": "blake2d",
	"dataFileList": {
		"path": "XX.nxs",
		"size": 0,
		"time": "",
		"chk": "XX",
		"_id": "69eXXXX"
	},
	"createdAt": "",
	"updatedAt": "",
	"__v": 0,
	"datasetExist": true
}

Expected Behaviour

{
        ....
	"dataFileList": [
               {
		   "path": "XX.nxs",
		   "size": 0,
		   "time": "",
		   "chk": "XX",
		   "_id": "69eXXXX"
	      },
         ],
}

Details

While the request is expected to return an OrigDatablock with only a single datafile in the dataFileList, it seems more adequate to maintain the dataFileList array format.

This useful to have more consistent schema at the frontend side instead of using just an object[] type .
see FileState

Also there is a risque of { $unwind: "$dataFileList" } at return multiple dataFileList objects like:

{ dataFileList: A }
{ dataFileList: B }
{ dataFileList: C }