[Currency System] Gem Currency Addition and Round Settlement Enhancements

[suhynnoh]

What

This PR includes improvements to the currency system, the addition of gem currency, the implementation of a round settlement screen, and the application of currency encryption. Key changes are as follows:

• Added gem data to the currency file and implemented related methods (saveGem, loadGem, loadDefaultGem).
• Added a gem field to the GameState class.
• Improved the currency settlement logic in RoundState (from game-level to round-level settlement).
• Updated ReceiptScreen and ScoreScreen classes to display information during rounds and at game end.
• Applied encryption when saving and loading currency.

Why

This PR aims to improve the game's currency system and enhance security, thus improving overall gameplay quality.

How to Test

1. Verify that the currency information is displayed correctly on the round settlement screen and game end screen.
2. Confirm that encryption works correctly when saving currency to a file.

Screenshots

This screenshot displays the "Receipt Screen" after a round. It shows:

• The coins obtained in this round.
• Displays the occurrence of hit rate bonus and clear time bonus.
• Also shows the STAGE SCORE and TOTAL SCORE to indicate the player's performance.

Displays the total coins earned during the game (EARNED $624 COINS!).

Additional Information

• Potential to add a feature for storing currency on a per-round basis in the future.
• Need to fix the bug where accuracy exceeds 100%.
• Differentiate between GameState.playTime and RoundState.roundTime.
• loadGem and saveGem have been tested internally as they are not yet linked to other functions.

[SEOKMINJUN]

It has been opened as draft pr, so I haven't checked the commit yet. I'll check out it when the conflicts are resolved and the review is ready.

[suhynnoh]

It has been opened as draft pr, so I haven't checked the commit yet. I'll check out it when the conflicts are resolved and the review is ready.

Understood. I will leave a comment once the conflicts are resolved and the review is ready.

[suhynnoh]

It has been opened as draft pr, so I haven't checked the commit yet. I'll check out it when the conflicts are resolved and the review is ready.

The conflicts have been resolved, and the pull request is now open for review.