Making the "tpl_msg_to_team" canceling message more informative

New feature / modification

What does this MR do?

Description:

Added a...

• relative date (if the date is yesterday, today or tomorrow otherwise it will be empty)
• day of the week (monday - sunday)
• time (24h format)

...to the "tpl_msg_to_team" message when canceling a pickup.

Examples (screenshots below):

• Freitag, 28. Sep., 09:20 Uhr [...]
• Heute, Dienstag, 25. Sep., 20:00 Uhr [...]

How confident are you it won't break things if deployed?

Should work. I checked other occurrences of niceDate() and everythink seems to work like before

Links to related issues

I think there are none.

Motivation

I beleive it helps users making a faster decision without having to look at the calender for the weekday or the store for the pickup time.

Screenshots

Before (no weekday, no time):

Not today or tomorrow:

No impact on the list of pickup date but could be used here as well:

Team message:

Today:

Checklist

• added a test, or explain why one is not needed/possible...
• no unrelated changes
• asked someone for a code review
• joined #foodsharing-beta channel at https://slackin.yunity.org
• added an entry to CHANGELOG.md (description, merge request link, username(s))