[FTP Connector][ftp:ClientEndpointConfig]The list() method need to return more clear output

[isuruuy429]

Description:
The ftp:ClientEndpointConfig returns an output as below. Assume we have a text file.

2020-01-12 22:17:50,616 INFO [isuruuyanage/basics] - extension=txt isFile=true scheme=ftp rootURI=ftp://ftp-user:ftp-user@192.168.108.65/ isWritable=true uri=ftp://ftp-user:ftp-user@192.168.108.65/home/ftp-user/in/dmajor1.txt lastModifiedTimestamp=0 isHidden=false publicURIString=ftp://ftp-user:***@192.168.108.65/home/ftp-user/in/dmajor1.txt path=/home/ftp-user/in/dmajor1.txt isFolder=false depth=5 size=0 pathDecoded=/home/ftp-user/in/dmajor1.txt name=dmajor1.txt isContentOpen=false friendlyURI=ftp://ftp-user:***@192.168.108.65/home/ftp-user/in/dmajor1.txt isAttached=true isExecutable=false isReadable=true fileType=file/n

We need to simply list down the files and the above provides a lengthy output. Better if we have a way to filter the file/directory names.

The resource is implemented as below.

@http:ResourceConfig {
        path: "/listFiles/{customizedLocation}"
    }

    resource function listFiles(http:Caller caller, http:Request request, string customizedLocation)returns error?{
        http:Response response = new ();
        var ftpResult = ftp->list(customizedLocation);

        if (ftpResult is error) {
            response.setJsonPayload({Message: "Error occurred while listing the files", Reason: ftpResult.reason()});
            log:printError("Error occurred while listing the files", ftpResult);
        }
        else
        {

            response.setJsonPayload({Files: ftpResult.toString()});
        }
        var httpResult = caller->respond(response);

    }

Further, in ftp connector tests[1], we have FileInfo[] as a type which now says it's an unknown type. Therefore it needs to be addressed as well.

[1] - https://github.com/wso2-ballerina/module-ftp/blob/master/ftp/src/ftp/tests/client_endpoint_test.bal