Visual indication (mode indicator) when cursor mode is engaged

The display of the black cursor when in cursor mode is not sufficiently indicative of the change in UI operation, leading to some confusion by users. In particular, the black cursor can be easily confused with a highlighted region, and may not be clearly visible under certain font sizes. A status indicator would help users identify which mode they are in, and selecting the indicator could open a quick-help panel telling them what each of the keys/mouse strokes would do.