feat: add safe typed access methods to YamlConfig

[devspexx]

Introduces null-safe, typed access methods directly on YamlConfig.

Added

• Optional-based getters:
  • getString, getInt, getBoolean, getDouble, getFloat
  • getStringList, get (raw object)
• Default-value getters:
  • getStringOrDefault, getIntOrDefault, getBooleanOrDefault, getDoubleOrDefault, getFloatOrDefault
• Utility method:
  • has(path)

Improvements

• Eliminates need for direct FileConfiguration access in most cases
• Prevents silent fallback values (e.g. int → 0 when missing)
• Improves API ergonomics and developer experience

Notes

• Fully backward compatible
• Designed to keep YamlConfig immutable and lightweight