[ENHANCEMENT] Better Shutdown Loading Screen

[TGIANN]

After the character UI is loaded, it closes the loading screen so we don't have to see the blond boy :D

• Old shotdown functions removed https://github.com/qbcore-framework/qb-loading/pull/17

Questions (please complete the following information):

• Have you personally loaded this code into an updated qbcore project and checked all it's functionality? yes
• Does your code fit the style guidelines? yes
• Does your PR fit the contribution guidelines? yes