[0.1.7] Player death

Added

• Add background game music when the player is playing the game. And paused it when the player was in the menu.
• Add player health and add HuD (Heads-up Display)
• Add Health for Player and all enemies (currently, all enemies have the same amount of health, but it will be changed in the future).
• Update the Health component when the player clicks the H keyboard (just for testing). There is no relation to the game. Just to check how to update the Health component and HuD width.
• Show the dead menu when the player is dead. Forbid to resume the game if the player is dead
• Add an out-of-bounce area when the player should die because it's a restricted area.

Changed

• Add a more complex game state. Add additional game states for Game and Menu states. Now Menu has Main and Dead sub-states.

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Full changelog