feat(cookie): generateCookie and generateSignedCookie helpers

[Soviut]

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

Closes #4281

I will write docs if this idea gets accepted.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.62%. Comparing base (89f4c96) to head (3c5c080).
⚠️ Report is 30 commits behind head on next.

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #4285      +/-   ##
==========================================
+ Coverage   91.61%   91.62%   +0.01%     
==========================================
  Files         170      170              
  Lines       10875    10888      +13     
  Branches     3099     3115      +16     
==========================================
+ Hits         9963     9976      +13     
  Misses        911      911              
  Partials        1        1              

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[yusukebe]

LGTM!

[yusukebe]

Hi @Soviut

Thank you for the PR! I think this feature is helpful. The implementation is also good. This is a new feature, so basically we can include this in the next minor release. Please wait for merging into the branch for the minor bump.