[req] FS or LS: TC background transfers viewer

[DrShark]

To avoid swinching between TC window and windows of background transfers, a good solution would be a locked panel with FS-plugin or QuickView (panel or separate window on 2nd monitor) which shows the info about background transfer windows (for copy/move/pack/unpack/del/download from list/empty BTM) started by current TC instance.

FS-plugin colud be made in Lister way, i.e. not a classic panel with virtual files, but custom window with UI (like TConsole fs-plugin). LS-plugin colud be registered to fake extension.

It could show an information for/from each backround transfer window, like:
* state/status (going/paused/stopped/not started)
* number of files for each job (already transfered, to transfer, and total)
* currently transfering file info (name, source and target paths)
* progress, maybe in progressbar form, for copied file and maybe general progress (if it's possible to get it from TC)
for each transfer window
* possibility to switch (focus) to any opened window of background transfer...