refs: https://github.com/TryGhost/Team/issues/1462
- added back in the main title to the top chart
- brought back the main metric background and centered buttons
- adjusted lots of spacing
- made the chart ticks for main graph dynamic
- improved the look of the breakdown graph
refs: https://github.com/TryGhost/Team/issues/1507
- changed the layout over to use css grids instead of the random flex and divs
- cleaned up the based dashboard-v5 file so its rendering much cleaner components
- refactored and took out a ton of old css that wasn't needed anymore
- moved the dashboard-v5 css into it's own css file to keep things cleaner
- includes a few stylistic changes along the way
