S3: Add Notifications for Restore-actions

[bblommers]

See @7363

@tsugumi-sys The restore_object-function was implemented in S3, it was just hidden in responses.py.
This PR:

• extracts the logic into the models-class
• Adds a notification when a Restore-action is initiated and completed

Any feedback/improvements that you can see?

[tsugumi-sys]

Thanks, @bblommers!
Oh, I missed restore_object implementation in moto!
LGTM :)

[codecov]

Codecov Report

Attention: Patch coverage is 96.29630% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 95.80%. Comparing base (9aef694) to head (435ef47).
Report is 94 commits behind head on master.

Files	Patch %	Lines
moto/s3/models.py	95.83%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #7455      +/-   ##
==========================================
- Coverage   95.88%   95.80%   -0.08%     
==========================================
  Files         843      849       +6     
  Lines       82578    83739    +1161     
==========================================
+ Hits        79178    80226    +1048     
- Misses       3400     3513     +113     

Flag	Coverage Δ
servertests	32.30% <18.51%> (-0.22%)	⬇️
unittests	95.77% <96.29%> (-0.08%)	⬇️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

This is now part of moto >= 5.0.4.dev5