downloads chart improvements

[dominikg]

• the filename for generated chart downloads should contain package name and date range
• the minimap start and end date show up as 1 week ranges, leading to a confusing 4 dates showing on hover, should just show actual dates, or no dates at all given the huge pickers above
• changing the start date one day back leads to a steep fall down a cliff at the end (assuming that week ranges don't match up anymore and the last one is just one day) - so better to sync end date to the closest end of nex interval?

[graphieros]

In PackageDownloadAnalytics.vue:

• minimap tooltips: I think we can leverage zoom.customFormat to display end/start dates only for the weekly granularity. I'll make the process simple by updating vue-data-ui to locate the tooltip (left or right) to parse the date properly, and keep weekStart and weekEnd accordingly.
• I wonder if we need better date pickers that adapt to the granularity

[graphieros]

I also noticed:

• translations of the granularity are not used on the yAxis label

[btea]

the filename for generated chart downloads should contain package name and date range

#212 Part of it is completed, but the name does not include a specific time. Should we add it?

[graphieros]

#212 Part of it is completed, but the name does not include a specific time. Should we add it?

I have a PR open #230 on which I can do that, as I made some changes to fix the minimap tooltip issue

Edit: pushed in 027f5f3

[graphieros]

✅ filenames: #846
✅ minimap date labels: #691
✅ downloads steep falls: #1177