Drill down by clicking on a bar/wedge opens page in new window/tab - should be same tab

[rouilj]

The charts with just one group (bar, pie, horizontalbar but not stacked/multibar) are opening in a new window and not in the same window when drilling down.

Please fix this.

[rouilj]

Also add a test to @varshi-123's test code to detect the working case:

find all a tags with xlink:href and verify that the target property on the a is correct

Work with @varshi-123 to commit your test.

[ashrith-UMB]

Clicking on a bar/wedge now will open in the same tab. commit : https://github.com/UMB-CS682-Team-02/tracker/commit/0fca0bb395e8d0219bba50a63a69a190500c5424

[rouilj]

LGTM