Rework graphs

[isakstenstrom]

This PR reworks some of the graphs for a invocation.

The tabs Runners, Action Cache, and ActionData has been combined into the ActionStatistics, and some graphs have been modified and some removed.

• The Action Runner Data table has been removed, since it shows almost exactly the same data as the Action Runners Breakdown graph.
• The Miss Detail Data table has been removed, since it shows almost exactly the same data as the Miss Detail Breakdown graph.
• Converted the Actions table from the Action data tab to a Pie-chart.
• Changed the colors for the Action Cache Overview chart so that the percentage is readable in both light and dark mode. It used to blend it with the color of the bars in the chart.

Result:

The tabs Timing and Network has been merged into a single tab, called System Metrics.

Result:

Closes #90

[isakstenstrom]

@trey-ivy, @mortenmj Would you care to review this? It is kind of a blocker for #143.