Add meta-data: First change, last change; name of rater

[nicebread]

Please add datetime of: "created" and "last change" to the results json. (Maybe more metadata will come later). For transparency reasons, display all metadata that is saved in the json also on the "Author" tab.

Rename author tab to "Author / Metadata", and add a field "Name of external rater (optional)".

[alpkaanaksu]

[alpkaanaksu]

Now we can insert variable values into info items. I also implemented typed-insertions:

date_created = 1693475745498 (millis)

$date_created -> "1693475745498"

$date_created@datetime -> "31/08/2023, 11:55:45"

$date_created@date -> "31/08/2023"

We can implement other types if needed in the future.