define control-click-drag on table

After https://github.com/twosigma/beakerx/issues/5456 we still have a problem because a user might want to select just a substring of a cell.
but is it possible to have click-and-drag be used both for select text and selecting cells?
in theory could start out text selection and monitor the drag and if it stays within a cell it stays text but if the mouse moves far enough to leave the cell, it becomes a cell selection. Maybe too complicated or surprising.

Simpler: a modifier key like control can indicate it's a normal text selection, and we just revert to the browser native text selection.