Add an asset server

[waynemwashuma]

Objective

Introduces an asset management system refactor, replacing the previous asset loading approach with a centralized asset server.

Solution

The previous asset system had loading logic distributed across multiple systems and plugins. This PR consolidates all asset loading management into a centralized AssetServer that:

• Handles asset loading, caching, and lifecycle management
• Provides a unified API for loading assets of any type
• Manages asset parsers and their verification
• Tracks asset load states (Unloaded, Loading, Failed, Loaded)
• Emits load events for success and failure scenarios

Other changes include:

• Adding more details to success (AssetLoadSuccess) and failure (AssetLoadFail) events(now carrying typeId, assetId, and path).
• Removing the obsolete AssetBasePath.
• Introducing systems to flush and forward load events to the ECS event queue.
• Added AssetServerPlugin to set up the server and its supporting systems.
• Updated AssetPlugin and AssetParserPlugin to interact with the server.

The solution was taken to:

• Reduce code duplication in asset loading logic
• Provide consistent asset handling across all asset types
• Improve error reporting and debugging capabilities
• Enable proper asset caching and reuse
• Simplify the API for developers using assets

Showcase

Loading assets with the new AssetServer:

// Before
import { AudioAssets } from 'wima'
const audioSources = world.getResource(AudioAssets)
const handle = audioSources.load('assets/audio/hit.mp3')

// After  
import { AssetServer, Audio } from 'wima'
const server = world.getResource(AssetServer)
const handle = server.load(Audio, 'assets/audio/hit.mp3')

MigrationGuide

Several breaking changes have been introduced:

• All instances of Assets.load() should be replaced with AssetServer.load()
• Asset load events are now managed through the AssetServer instead of individual asset systems
• AssetBasePath resource has been removed, an alternative will be provided later.

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.