heaptrack_gui: Chart toolbar
heaptrack_gui: This MR adds a new toolbar to all ChartWidget instances with the following four features:
- "Export As..." button allowing the export of the currently displayed chart
- Checkboxes for showing/hiding the total and the detailed cost graph, respectively
- Spin box for adjusting the number of displayed symbols in the detailed cost graph
- Legend for the charts depicting symbols marked in the detailed cost graph
Tagging: @teams/vdg
Edited by Christopher Roemheld