Allow more than one weight entry per day

[rolandgeider]

At the moment, it's only possible to add one weight or measurement entry per day. While it doesn't make much sense to log this several times per day, it also doesn't hurt and it would make some of the logic more easy.

TODO: change the models from date to date time and remove the unique_together

[Dieterbe]

A trainer on our discord brought up a good use case: water cuts for making weight categories (eg in powerlifting comp)

[scrapcode]

I am taking a stab at this but I think clarification needs to be made on any desired restrictions, or none at all.

Currently there are many tests that check that seed data helper functions filter out weight entries for existing dates, date addition functions update existing entries when made within N days, etc.

Are there any restrictions desired here, for example, only one weight entry per day? Or remove such restrictions altogether?

[rolandgeider]

just remove them alltogehter :)