New prototype level: Escape!

• A brand new level with an intense pace and spikes.
• A lot of spikes.
• Implements a new checkpoint system.
• Really hoping you love spikes.
• To help focus on one prototype level at a time, "Sapphire Theft" is not in the game anymore.

UI improvements

• Added confirmation for Rewind and Restart level buttons.
• In-game menu and game over menu have more explicit restart options: "restart level" and "load last checkpoint" (which is usually the beginning of the phase).
• General style improvements
• Some UIs still have the old style (level select, shop) as they need to be reworked.

Misc

• "Infiltration phase" is renamed "Loot phase" to better represent the goal of this phase.
• Camera can be moved with arrows or WASD keys.
• Alarms are replaced by Alarm Doors. They have the same role, but they are more intuitive to understand (Trin can't trigger the alarm, and Invisibility won't prevent the alarm from triggering either).
• Emerald Theft (part 2): Triangle key is now in a chest to better show that it can't be looted by Trin
• Amethyst Theft: Level entrance is now in exterior

Fixes

• Fix "End scout phase" not appearing after restarting a level when all objectives are complete.