Add optional resource getters to World

[waynemwashuma]

Objective

Introduce optional resource getters that allow resources to be retrieved without throwing when they do not exist.

Solution

Added optional variants of the World resource getter APIs while preserving resource alias resolution.

Changes Made

• Added World.getOptionalResource() for type-based lookups.
• Added World.getOptionalResourceByTypeId() for type ID lookups.

Why This Approach

Required getters continue to assert when a resource is missing, while optional getters return undefined.

Showcase

Before

const resource = world.getResource(TestResource)
// Throws when the resource does not exist

After

const resource = world.getOptionalResource(TestResource)

if (resource !== undefined) {
  // Use the resource
}

Migration Guide

No migration required.

Checklist

• I have updated the documentation accordingly.
• I have added tests to cover my changes.