Add WithRetention to automatically remove expired data

[nakabonne]

Ref #18

[codecov-commenter]

Codecov Report

Merging #22 (c6e8159) into main (2fd043f) will decrease coverage by 0.75%.
The diff coverage is 48.94%.

@@            Coverage Diff             @@
##             main      #22      +/-   ##
==========================================
- Coverage   66.05%   65.31%   -0.74%     
==========================================
  Files          19       19              
  Lines         913      954      +41     
==========================================
+ Hits          603      623      +20     
- Misses        218      234      +16     
- Partials       92       97       +5     

Impacted Files	Coverage Δ
fake_partition.go	25.00% <0.00%> (-3.57%)	⬇️
partition_list.go	82.83% <0.00%> (ø)
disk_partition.go	53.13% <33.34%> (-3.23%)	⬇️
storage.go	55.90% <55.89%> (-0.38%)	⬇️
memory_partition.go	78.04% <100.00%> (+0.17%)	⬆️

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