Export data to a spreadsheet report

[benoit74]

Mentioned in offspot/kiwix-hotspot#612, some users might be interested in a report they could download when visiting schools.

I suggest to implement for v1 an "export" button which extracts a spreadsheet with existing data.

[rgaudin]

I'd postpone this to a later version, based on feedback and needs.

[rgaudin]

@kelson42 @Popolechien, WDYT? I think widening maintenance area is not wise until we've confirmed we're doing the right (and useful) thing.

[Popolechien]

This is needed but agree we can put on hold until v2.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be now be reviewed manually. Thank you for your contributions.