fix: Ensure options are initialized and handle null cases in SlotDisp…

[BungeeDEV]

This pull request improves the robustness and readability of the SlotDisplayEntity class by ensuring configuration options are never null and by making property assignments more defensive. Additionally, it refactors code formatting for better clarity and adds null checks before accessing configuration options.

Robustness and Null Safety:

• Ensured that the options field is never null by initializing it with a default value if necessary in the constructor.
• Added null checks before accessing options.VANILLA_SCALE and related properties in multiple methods to prevent potential NullPointerExceptions. [1] [2]

Code Formatting and Readability:

• Reformatted property assignments in several methods to improve readability, breaking long lines and aligning parameters for clarity. [1] [2] [3] [4]