EDU-1763 Handle media trash requests

[ahelmberger]

Closes https://educandu.atlassian.net/browse/EDU-1763

[codecov]

Codecov Report

❌ Patch coverage is 90.19608% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.26%. Comparing base (3e4e217) to head (ad053af).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/lambda/index.js	82.35%	3 Missing ⚠️
src/lambda/urls.js	50.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #13      +/-   ##
==========================================
- Coverage   93.75%   92.26%   -1.49%     
==========================================
  Files           6        7       +1     
  Lines         160      194      +34     
  Branches       34       42       +8     
==========================================
+ Hits          150      179      +29     
- Misses         10       15       +5     

Files with missing lines	Coverage Δ
src/lambda/config.js	68.42% <ø> (ø)
src/lambda/cookie-helper.js	100.00% <100.00%> (ø)
src/lambda/request-helper.js	100.00% <100.00%> (ø)
src/lambda/urls.js	64.70% <50.00%> (-4.53%)	⬇️
src/lambda/index.js	95.31% <82.35%> (-4.69%)	⬇️

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