Review special mode for very small browser windows

Users sometimes make the TVB browser window very small to check on other (related) stuff, e.g. cluster state, reviewing source data, waiting for operations finishing (!!!) etc.

It could be beneficial to catch this "very-small-window" mode w/ CSS media queries and enable a much reduced display variant. E.g. the view could be reduced to bare essentials. That would e.g. be just the state of background operations.