refs https://github.com/TryGhost/Team/issues/1512
Adds the new endpoint `/stats/subscriptions/` which provides data for
the paid mix and paid breakdown charts.
Made the filledMissingDates function more generic by passing in a
`copyData` function which is used to populate a date from the previous
days data, if the data for that date is missing.
refs: https://github.com/TryGhost/Team/issues/1531
- investigated how to make the layout not break on resize
- using a width 99% hack to make chartjs react properly
- redid the markup for the minicharts for more stable loading
- added in a subtle gradient for the mrr minichart
refs: https://github.com/TryGhost/Team/issues/1547
- moved to horizontal bar chart
- made the tooltips work differently for this
- added in a simple legend for the cadence chart
- style issues remain but wanted to get functionality in there first
refs: https://github.com/TryGhost/Team/issues/1531
- broke apart the combined chart
- added back in the paid mix chart
- separated out the mini charts into separate components
- made top chart work with total, paid and free
- added in an overview section back at the top for total, paid, free
- made metric labels and values larger and easier to parse
Co-authored-by: Simon Backx <simon@ghost.org>
