[Metric] Style fixes and improvements

[gvnmagni]

Style fixes that would be great to tackle in order to improve the UI of our Metric Chart, some of these will need dedicated sub-issues but I wanted to collect of details that I am seeing so that we have a clear idea of the work to do and then we can face these issue one by one

The ultimate goal is to get this following image coming from design exploration:

It is, unfortunately, a combination of things that depends on multiple factors but we can get there, one by one:

• Margins between internal elements (between title and subtitle, between value and secondary value, between progress bar and text... we would probably require to make some CSS adjustment to the text blocks
• Progress bar style (smaller width on small breakpoints, additional border on colored bar, rounded bar)
• Secondary Value, add possibility to color only icon for a more elegant and clean UI (this would be then our new default)
• Monospaced font (coming from a different issue/activity)
• Font-weight adjustment and customisation for Primary Value