Provides store method for retrieving traffic usage data based on
period parameter, and UI + ui hook with the new chart for displaying
traffic usage data spread out over selectable month.
In this PR we copied and adapted a plugin written by DX for highlighting
a column in the chart:
There are some minor improvements planned which will come in a separate
PR, reversing the order in legend and tooltip so the colors go from
light to dark, and adding a month -sum below the legend
## Discussion points
- Should any of this be extracted as a separate reusable component?
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Co-authored-by: Nuno Góis <github@nunogois.com>
## About the changes
Implements a new store for collected traffic data usage that connects to
the new table `stat_traffic_data` primary key'd on [day, trafficGroup,
status_code_series].
Day being a date
Traffic group being which endpoint is being counted for, ie /api/admin,
/api/frontend etc
Status code series grouping 2xx status responses and 304 into their
respective 200 / 300 series.
No service here, this is for pro/enterprise
