Fixes required in new insights

[doppleware]

• @ionuiux please update the design for the "Low Usage" and "Slow Endpoint" it does not look good currently

• Decrease main values font size to 12 (already updated in design system)

• Check toolbar button sizes @ionuiux ?
• The first button from the right should always be a primary (text and icon), in all insights
• Cards are too far apart, please make margin a little smaller

• Fix the insights page background color, it is a bit brighter than the design in the mockup. @ionuiux please provide details.

• Endpoint dropdown should open when clicking on an empty area, not just on the caret

• Adjust Jira ticket hint to the new design @ionuiux

[kshmidt-digma]

Related to #681