[Unit Tests] Create unit tests for GameState
# Feature Request
## Summary
Create unit tests for the `GameState` class to validate referee updates, world‐state updates, score tracking, and orientation flags.
## Acceptance Criteria
- [ ] Add `GameStateTest.cpp` under `unit_tests`.
- [ ] Test `updateRefereeState(refData)` changes internal `gameState` and `getRefereeData()`.
- [ ] Test `updateWorldState(ballData, friendlyTeam)` sets `isBlueOnPositive()` flag and updates `ball`.
- [ ] Test `getBlueScore()`/`getYellowScore()` after sequential calls.
- [ ] Test `isBlueOnPositive()` toggles based on input.
- [ ] Test `getRefereeState()` reflects last referee command.
- [ ] All tests compile under Ninja and pass via `./build/unit_tests`.
## Design / Technical Approach
1. Include `GameState.h`, stub `RefereeData`.
2. Feed sample referee data, assert state changes.
3. Feed world‐state updates, assert orientation and scores.
## Dependencies
- `GameState.h`, `RefereeData.h`, `BallData`.
- Boost.UT framework.
## Testing Plan
- Build:
```bash
ninja
```
- Run:
```bash
./build/unit_tests --run_test GameState
```
issue