Add booking email with ics attachment

[miaulalala]

Fixes #3855

Before	After
Subject: Your appointment "Have Lunch With Me" needs confirmation	Subject: Your appointment "Have Lunch With Me" with admin needs confirmation

New booking info email:

[miaulalala]

Maybe extend the text a bit... IDK, the text isn't very descriptive at the moment.

[codecov]

Codecov Report

Base: 29.50% // Head: 29.84% // Increases project coverage by +0.34% 🎉

Coverage data is based on head (aa23053) compared to base (c1c574c).
Patch has no changes to coverable lines.

❗ Current head aa23053 differs from pull request most recent head cabc0f7. Consider uploading reports for the commit cabc0f7 to get more accurate results

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #4579      +/-   ##
============================================
+ Coverage     29.50%   29.84%   +0.34%     
- Complexity      330      338       +8     
============================================
  Files           220      220              
  Lines          7674     7719      +45     
  Branches       1002     1002              
============================================
+ Hits           2264     2304      +40     
- Misses         5410     5415       +5     

Flag	Coverage Δ
javascript	20.57% <ø> (ø)
php	69.41% <ø> (+0.61%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
.../calendar/lib/Service/Appointments/MailService.php	98.03% <0.00%> (-1.97%)	⬇️
...lendar/lib/Service/Appointments/BookingService.php	82.05% <0.00%> (-1.95%)	⬇️
src/views/Appointments/Conflict.vue	0.00% <0.00%> (ø)
...lib/Service/Appointments/BookingCalendarWriter.php	0.00% <0.00%> (ø)

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[miaulalala]

/rebase

[JMoVS]

@miaulalala nice work! But is there an option to skip the email verification step?

[miaulalala]

@miaulalala nice work! But is there an option to skip the email verification step?

Hm it's a feature to think about maybe. But for now, no, there isn't. You can open a feature request on this repo, then we have that documented as a ticket.