Tighten up UI of new performance dashboard

I think we can tighten up the UI of the new performance dashboard. A few thoughts from my side:

• I think we can shrink the font size a little for the title of each component, for example Kubernetes. It looks a little strange to me with it being the same font size as the Environment: production text.
• I think we can tighten how the additional margin on the title bar for each component, to be smaller.
• On the charts, lots of whitespace between metric name and the chart.
• I think we should increase the chart title font a bit, and then reduce the size of the axis titles. It's strange they are larger than the title. Same goes for the axis range font. (e.g. 0, 5, 10, 15)
• The charts look like a good size horizontally, but seem slightly too large vertically. Maybe decrease vertical height just a little?
• There is a lot of whitespace after the legend at the bottom. Ideally the bottom of the "card" should have just a small margin underneath the legend.

The other issue is that the hover bars are no longer sync'd across the charts.