Improve t5memory status response handling

Status query differs between versions 0.4.x and 0.5.x of t5memory
Status query documentation
Request parsing documentation

The problem
In version 0.5.x there is no tmxImportStatus field in response after memory restart so we have for such memories status unknown (see documentation)

The solution
Need to change parsing status and make it to be available in case status is available in response and there is no tmxImportStatus field