Send confirmation email in user locale

[nijel]

When somebody books an appointment, I will get a confirmation email localized in his language. It's not that big deal as all information is also added to my calendar, but still, I would prefer to receive email in language I understand rather than in language that the other person prefers.

To reproduce:

• Use English in Nextcloud
• Configure appointments
• Enable: Email Me when an appointment is: Confirmed
• Let somebody with browser configured to German confirm an appointment
• You will receive: "Termin bestätigt: Name Surname, 26.11.20, 15:15"

[nooblag]

Yes, it would be great if this plugin used the Nextcloud default_locale or force_locale config.php setting, and/or pulled the user's language setting.