display sync status, progress (feature request)

Please allow to display sync status and progress e.g. at status bar bottom edge (could be configurable the location) continuously (almost in real-time). This applies to all platforms where Keybase works and both CLI and GUI. At CLI there is currently:
`keybase fs sync show`

But it shows only that moment when pressed Enter. Would propose to allow monitor it periodically, e.g. configurable option, could be in seconds, minutes, hours or turned off and shows only when manually clicked on the icon.

E.g. shows up and download size, speed and when to click that applet, it opens dialog box where I can already precisely see, what files currently are up- or downloading (name, file size, how much is already transfered and how much remained per file) and how long it takes per each file and in summary to finish and how much time has been spent already. Such up-, download dialog box is at [MegaSync](https://mega.nz/) for instance.
There could be also bubble information window opening automatically when moving mouse over that applet.

Also per each line showing up- or download, there could be a small icon in the end of line, e.g. small cross or trash can icon to pause or cancel transfer process per file or all together.

Together with KBFS quota display (#3436 ) it would be a good improvement about showing current status and progress and ETA to end data transfer and showing exactly which files are currently up- or downloading. This gives a flexible control over data transfer.

The issue names `keybase fs sync show` as the current CLI entry point; start there and inspect how sync status is exposed to the CLI and GUI. No source files or tests are identified, and completion would require agreeing on cross-platform status display, configurable refresh behavior, transfer details, and pause or cancel controls.

Written by the indexing model from the issue text.