feat: websocket proxy

[Netail]

Summary

Added a websocket proxy helper. A feature that I and assumably many others liked from node-http-proxy.

Related https://github.com/orgs/honojs/discussions/4086 & https://github.com/orgs/honojs/discussions/3588

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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.02%. Comparing base (16c4e38) to head (33194b1).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4939      +/-   ##
==========================================
+ Coverage   93.00%   93.02%   +0.01%     
==========================================
  Files         177      178       +1     
  Lines       11999    12031      +32     
  Branches     3617     3623       +6     
==========================================
+ Hits        11160    11192      +32     
  Misses        839      839              

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[Netail]

Is there anything else I need to add stuff to? e.g. docs website (Unfamiliar with the internals of this project). Also, is there an alpha / nightly build so I can test it internally?