feat: delete the part files when the download process interrupted

[LinuxSuRen]

No description provided.

[codecov]

Codecov Report

Merging #356 (30691fa) into master (d669e7f) will decrease coverage by 0.20%.
The diff coverage is 87.50%.

@@            Coverage Diff             @@
##           master     #356      +/-   ##
==========================================
- Coverage   60.40%   60.20%   -0.20%     
==========================================
  Files          64       64              
  Lines        3384     3450      +66     
==========================================
+ Hits         2044     2077      +33     
- Misses       1235     1268      +33     
  Partials      105      105              

Flag	Coverage Δ
unittests	60.20% <87.50%> (-0.20%)	⬇️

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

Impacted Files	Coverage Δ
pkg/net/multi_thread.go	85.84% <81.25%> (-1.39%)	⬇️
pkg/net/http.go	79.48% <100.00%> (+0.76%)	⬆️
cmd/install.go	34.75% <0.00%> (+0.25%)	⬆️

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