Fix front page stats

This merge request fixes the way the numbers are gathered for the statistics on the front page.

It now shows an accurate picture to the user on the page whether anonymous or not.

Fixes #514 (closed)

changed milestone to %Code cleanup

added bug confirmed labels

added 10 commits

• 311df5b5...a79f92df - 6 commits from branch django3_migration
• 4e428cd1 - [attestations] Add for_user method
• bceddcc4 - [reports] Add for_user method
• 0b0a79b7 - [statistics][templatetags] Add user accurate computation method
• ea610b65 - [statistics][templates] Simplify user usage

Compare with previous version

enabled an automatic merge when the pipeline for ea610b65 succeeds

merged

mentioned in commit 9fd1fd56

mentioned in issue #514 (closed)