refactor: migrate the project to golang

[efectn]

This PR migrates old nodejs codebase to golang with more unit tests and better in terms of optimization and speed.

Todo list:

• Add unit tests for handler.
• Check whether key generators are compatible with old ones. Maybe add support for dictionary key generator, too.
• Update docker stuff.
• Remove old files.
• Router codes need to be revised, it can be better.
• Split routing stuff from cmd/main.go
• Code cleanup.
• CI actions for linting, testing and building.
• Rate limit support.