fix: add CDN cache header on search api

[codecov[bot]]

Codecov Report

Merging #583 (77f38a7) into master (ab2fde7) will decrease coverage by 0.09%. Report is 44 commits behind head on master. The diff coverage is 96.27%.

@@            Coverage Diff             @@
##           master     #583      +/-   ##
==========================================
- Coverage   97.02%   96.94%   -0.09%     
==========================================
  Files         174      180       +6     
  Lines       16588    17360     +772     
  Branches     2177     2250      +73     
==========================================
+ Hits        16095    16829     +734     
- Misses        493      531      +38     

Files Changed	Coverage Δ
config/config.default.ts	84.61% <47.36%> (-3.81%)	:arrow_down:
app/port/webauth/WebauthController.ts	85.59% <78.94%> (+0.53%)	:arrow_up:
app/core/service/PackageSyncerService.ts	98.21% <92.00%> (-0.01%)	:arrow_down:
app/core/service/PackageSearchService.ts	93.83% <93.83%> (ø)
app/common/PackageUtil.ts	97.85% <94.44%> (-1.19%)	:arrow_down:
app/core/event/SyncESPackage.ts	96.80% <96.80%> (ø)
app/common/FileUtil.ts	100.00% <100.00%> (ø)
app/common/UserUtil.ts	100.00% <100.00%> (ø)
app/common/adapter/CacheAdapter.ts	100.00% <100.00%> (ø)
app/common/adapter/NPMRegistry.ts	100.00% <100.00%> (ø)
... and 39 more

... and 2 files with indirect coverage changes