feat: Implement in-memory database and enhance worker management logic in Go

[fol21]

feat: implements two new Go modules: an in-memory key-value database with time-travel and TTL support, and a worker registration system with support for promotions, salary calculation, and ranking. Comprehensive test coverage is also provided for the database module.

In-Memory Database Implementation (Questions/in_memory_database/go/simulation.go):

• Implements a multi-level in-memory key-value database to the level 3.

Worker Registration System (Questions/workers/go/simulatio.go):

• Adds a worker management system that supports worker registration, until level 3.