Remove the y-dimension from bar hovering.

[samussiah]

i.e. only track the x-dimension of the mouse over the chart so that the user can click anywhere in the vertical of a bar to select it, to avoid the inability to click itsy bitsy teenie weenie one-record bars. also throw some grayed-out bars along the entire vertical to indicate which bar the user is hovering over.

Test notes

• Hovering/clicking anywhere in the chart highlights the bar underneath the mouse vertically, regardless of whether the mouse is over the bar itself.

[jwildfire]

Drawing invisible bars with 100% height in the same might be easier than just tracking x coordinate.

[emmorris]

Jack requested an improvement that seems to align with this issue. During the 11-27-18 meeting he mentioned that some of the small bars are difficult to click on and it would be better if he could click the space above them too.

[dschwentker]

Tested and confirmed that hovering anywhere on the chart highlights the vertical bar under the mouse. Also confirmed you can click anywhere in the vertical space in or above a bar to select the bar and display the listing underneath the chart, or deselect a bar and have the listing be removed from the page.