[US-02] Alternating shooting with feedback

Description

Implements alternating shooting functionality for the Battleship game as described in issue #2.

Changes

• Added Game class to manage game state and alternating turns
• Added Player class to represent players and handle shooting logic
• Enhanced Board class with shot tracking and validation
• Added comprehensive tests for alternating shooting functionality
• Fixed compilation issues with missing Orientation enum and constructor in Ship class

Features Implemented

• Players take turns shooting at each other's boards
• Shot validation prevents duplicate shots and invalid coordinates
• Feedback provided for hits, misses, and invalid shots
• Game state tracks current player and game over conditions
• All acceptance criteria from issue #2 are met

Acceptance Criteria Verified

✅ When firing at A1 for the first time, a message appears showing hit or miss, and that field becomes marked ✅ When the same field is targeted again, the shot does not go through, and the next player acts ✅ After one shot cycle finishes, the control changes so that only the other player can continue

Closes #2